Name: cultivation of the marine pelagic tunicate dolioletta gegenbauri (uljanin 1884) for experimental studies
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We are grateful to the many persons who have contributed accumulated knowledge to this project over the years including G.-A. Paffenh&#246;fer and D. Deibel who originally developed these protocols. M. K&#246;ster, and L. Lamboley have also contributed significantly to the development of these procedures.&#160; N.B. L&#243;pez-Figueroa and &#193;.E. Rodr&#237;guez-Santiago generated the estimates of doliolid abundance provided in Table 1. This study was supported in part by the US National Science Foundation awards OCE 082599, 1031263 to MEF, collaborative projects OCE 1459293 and OCE 14595010 to MEF and DMG and, the National Oceanic and Atmospheric Administration award NA16SEC4810007 to DMG. We are grateful to the hardworking and professional crew of the R/V Savannah. Lee Ann DeLeo prepared the figures, Charles Y. Robertson proofread the manuscript and, James (Jimmy) Williams manufactured the plankton wheel

1. Preparing culturing facilities for rearing D. gegenbauri
NOTE: All materials and equipment required are listed in the Table of Materials.
<ol>
	<li>Prepare 1 M Sodium Hydroxide (NaOH), 0.06 M Potassium Permanganate (KMnO4) solution. To prepare this solution, dissolve 400 g of NaOH into 10 L deionized water. Add 100 g of KMnO4 to the NaOH solution and mix well.</li>
	<li>Prepare a 0.1 M Sodium bisulfite (NaHSO3) solution by dissolv...

<ol>
	<li>Banse, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Zooplankton+&#8211;+Pivotal+role+in+the+control+of+ocean+production.">Zooplankton &#8211; Pivotal role in the control of ocean production.</a> Ices Journal of Marine Science. 52 (3-4), 265-277 (1995).</li><li>Wilson, S. E., Ruhl, H. A., Smith, K. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Zooplankton+fecal+pellet+flux+in+the+abyssal+northeast+Pacific:+A+15+year+time-series+study.">Zooplankton fecal pellet flux in the abyssal northeast Pacific: A 15 year time-series study.</a> Limnology and Oceanography. 58 (3), 881-892 (2013).</li><li>Bode, A., &#193;lvarez-Ossorio, M. T., Miranda, A., Ruiz-Villarreal, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Shifts+between+gelatinous+and+crustacean+plankton+in+a+coastal+upwelling+region.">Shifts between gelatinous and crustacean plankton in a coastal upwelling region.</a> Ices Journal of Marine Science. 70 (5), 934-942 (2013).</li><li>Kiorboe, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Zooplankton+body+composition.">Zooplankton body composition.</a> Limnology and Oceanography. 58 (5), 1843-1850 (2013).</li><li>Holland, L. Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tunicates.">Tunicates.</a> Current Biology. 26 (4), R146-R152 (2016).</li><li>Walters, T. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diet+and+trophic+interactions+of+a+circumglobally+significant+gelatinous+marine+zooplankter,+Dolioletta+gegenbauri+(Uljanin,+1884).">Diet and trophic interactions of a circumglobally significant gelatinous marine zooplankter, Dolioletta gegenbauri (Uljanin, 1884).</a> Molecular Ecology. , (2018).</li><li>Piette, J., Lemaire, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thaliaceans,+the+neglected+pelagic+relatives+of+ascidians:+a+developmental+and+evolutionay+enigma.">Thaliaceans, the neglected pelagic relatives of ascidians: a developmental and evolutionay enigma.</a> Quarterly Review of Biology. 90 (2), 117-145 (2015).</li><li>Acu&#241;a, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pelagic+tunicates:+Why+gelatinous?.">Pelagic tunicates: Why gelatinous?.</a> American Naturalist. 158 (1), 100-107 (2001).</li><li>Alldredge, A. L., Madin, L. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pelagic+tunicates+&#8211;+unique+herivores+in+the+marine+plankton.">Pelagic tunicates &#8211; unique herivores in the marine plankton.</a> Bioscience. 32 (8), 655-663 (1982).</li><li>Wada, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evolutionary+history+of+free-swimming+and+sessile+lifestyles+in+urochordates+as+deduced+from+18S+rDNA+molecular+phylogeny.">Evolutionary history of free-swimming and sessile lifestyles in urochordates as deduced from 18S rDNA molecular phylogeny.</a> Molecular Biology and Evolution. 15 (9), 1189-1194 (1998).</li><li>Zeng, L. Y., Jacobs, M. W., Swalla, B. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coloniality+has+evolved+once+in+stolidobranch+ascidians.">Coloniality has evolved once in stolidobranch ascidians.</a> Integrative and Comparative Biology. 46 (3), 255-268 (2006).</li><li>Delsuc, F., Brinkmann, H., Chourrout, D., Philippe, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tunicates+and+not+cephalochordates+are+the+closest+living+relatives+of+vertebrates.">Tunicates and not cephalochordates are the closest living relatives of vertebrates.</a> Nature. 439 (7079), 965-968 (2006).</li><li>Garstang, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+morphology+of+the+Tunicata,+and+its+bearing+on+the+phylogeny+of+the+chordata.">The morphology of the Tunicata, and its bearing on the phylogeny of the chordata.</a> Quarterly Journal of Microscopical Science. 72 (285), 51-187 (1929).</li><li>Govindarajan, A. F., Bucklin, A., Madin, L. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+molecular+phylogeny+of+the+Thaliacea.">A molecular phylogeny of the Thaliacea.</a> Journal of Plankton Research. 33 (6), 843-853 (2011).</li><li>Godeaux, D., Bone, Q., Braconnot, J. C., Bone, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The Biology of Pelagic Tunicates. , 1-24 (1998).</li><li>Deibel, D., Lowen, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+review+of+the+life+cycles+and+life-history+adaptations+of+pelagic+tunicates+to+environmental+conditions).">A review of the life cycles and life-history adaptations of pelagic tunicates to environmental conditions).</a> Ices Journal of Marine Science. 69 (3), 358369 (2012).</li><li>Paffenh&#246;fer, G., K&#246;ster, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=From+one+to+many:+on+the+life+cycle+of+Dolioletta+gegenbauri+Uljanin+(Tunicata,+Thaliacea).">From one to many: on the life cycle of Dolioletta gegenbauri Uljanin (Tunicata, Thaliacea).</a> Journal of Plankton Research. 33 (7), 1139-1145 (2011).</li><li>Paffenh&#246;fer, G. A., Gibson, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Determination+of+generation+time+and+asexual+fecundity+of+doliolids+(Tunicata,+Thaliacea).">Determination of generation time and asexual fecundity of doliolids (Tunicata, Thaliacea).</a> Journal of Plankton Research. 21 (6), 1183-1189 (1999).</li><li>Conley, K. R., Lombard, F., Sutherland, K. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mammoth+grazers+on+the+ocean's+minuteness:+a+review+of+selective+feeding+using+mucous+meshes.">Mammoth grazers on the ocean's minuteness: a review of selective feeding using mucous meshes.</a> Proceedings of the Royal Society B-Biological Sciences. 285 (1878), (2018).</li><li>Bouquet, J. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Culture+optimization+for+the+emergent+zooplanktonic+model+organism+Oikopleura+dioica.">Culture optimization for the emergent zooplanktonic model organism Oikopleura dioica.</a> Journal of Plankton Research. 31 (4), 359370 (2009).</li><li>Denoeud, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Plasticity+of+Animal+Genome+Architecture+Unmasked+by+Rapid+Evolution+of+a+Pelagic+Tunicate.">Plasticity of Animal Genome Architecture Unmasked by Rapid Evolution of a Pelagic Tunicate.</a> Science. 330 (6009), 1381-1385 (2010).</li><li>Harrison, P. J., Waters, R. E., Taylor, F. J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+broad-spectrum+artificial+seawater+medium+for+coastal+and+open+ocean+phytoplankton.">A broad-spectrum artificial seawater medium for coastal and open ocean phytoplankton.</a> Journal of Phycology. 16 (1), 2835 (1980).</li><li>Ohman, M. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Zooglider:+An+autonomous+vehicle+for+optical+and+acoustic+sensing+of+zooplankton.">Zooglider: An autonomous vehicle for optical and acoustic sensing of zooplankton.</a> Limnology and Oceanography-Methods. 17 (1), 69-86 (2019).</li><li>Takahashi, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+situ+observations+of+a+doliolid+bloom+in+a+warm+water+filament+using+a+video+plankton+recorder:+Bloom+development,+fate,+and+effect+on+biogeochemical+cycles+and+planktonic+food+webs.">In situ observations of a doliolid bloom in a warm water filament using a video plankton recorder: Bloom development, fate, and effect on biogeochemical cycles and planktonic food webs.</a> Limnology and Oceanography. 60 (5), 1763-1780 (2015).</li><li>Deibel, D., Bone, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The biology of pelagic tunicates. , 171-186 (1998).</li><li>Gibson, D. M., Paffenh&#246;fer, G. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Feeding+and+growth+rates+of+the+doliolid,+Dolioletta+gegenbauri+Uljanin+(Tunicata,+Thaliacea).">Feeding and growth rates of the doliolid, Dolioletta gegenbauri Uljanin (Tunicata, Thaliacea).</a> Journal of Plankton Research. 22 (8), 1485-1500 (2000).</li><li>Haskell, A., Hofmann, E., Paffenh&#246;fer, G., Verity, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modeling+the+effects+of+doliolids+on+the+plankton+community+structure+of+the+southeastern+US+continental+shelf.">Modeling the effects of doliolids on the plankton community structure of the southeastern US continental shelf.</a> Journal of Plankton Research. 21 (9), 1725-1752 (1999).</li><li>Gibson, D. M., Paffenh&#246;ffer, G. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Asexual+reproduction+of+the+doliolid,+Dolioletta+gegenbauri+Uljanin+(Tunicata,+Thaliacea).">Asexual reproduction of the doliolid, Dolioletta gegenbauri Uljanin (Tunicata, Thaliacea).</a> Journal of Plankton Research. 24 (7), 703-712 (2002).</li><li>Frischer, M. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reliability+of+qPCR+for+quantitative+gut+content+estimation+in+the+circumglobally+abundant+pelagic+tunicate+Dolioletta+gegenbauri+(Tunicata,+Thaliacea).">Reliability of qPCR for quantitative gut content estimation in the circumglobally abundant pelagic tunicate Dolioletta gegenbauri (Tunicata, Thaliacea).</a> Food Webs. 1, 7 (2014).</li><li>K&#246;ster, M., Paffenh&#246;fer, G., Baker, C., Williams, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oxygen+consumption+of+doliolids+(Tunicata,+Thaliacea).">Oxygen consumption of doliolids (Tunicata, Thaliacea).</a> Journal of Plankton Research. 32 (2), 171-180 (2010).</li><li>Paffenh&#246;fer, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+hypothesis+on+the+fate+of+blooms+of+doliolids+(Tunicata,+Thaliacea).">A hypothesis on the fate of blooms of doliolids (Tunicata, Thaliacea).</a> Journal of Plankton Research. 35 (4), 919-924 (2013).</li><li>Takahashi, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sapphirinid+copepods+as+predators+of+doliolids:+Their+role+in+doliolid+mortality+and+sinking+flux.">Sapphirinid copepods as predators of doliolids: Their role in doliolid mortality and sinking flux.</a> Limnology and Oceanography. 58 (6), 1972-1984 (2013).</li><li>Mart&#237;-Solans, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oikopleura+dioica+Culturing+Made+Easy:+A+Low-Cost+Facility+for+an+Emerging+Animal+Model+in+EvoDevo.">Oikopleura dioica Culturing Made Easy: A Low-Cost Facility for an Emerging Animal Model in EvoDevo.</a> Genesis. 53 (1), 183-193 (2015).</li><li>Nishida, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+the+appendicularian+Oikopleura+dioica:+Culture,+genome,+and+cell+lineages.">Development of the appendicularian Oikopleura dioica: Culture, genome, and cell lineages.</a> Development Growth &amp; Differentiation. 50, S239-S256 (2008).</li></ol>

The capacity to culture doliolids has been established over the past several decades and has been used to support research in several areas. Experimental studies in our laboratories have supported the publication of at least 15 scientific studies focused on the feeding and growth18,26, reproduction18,28, diet6,29, physiology30</s...

Zooplankton account for the largest animal biomass in the ocean, are key components in marine food webs, and play important roles in ocean biogeochemical cycles1,2. Zooplankton, although comprised of a huge diversity of organisms, can be grossly distinguished into two categories: gelatinous and non-gelatinous with few intermediate taxa3,4. Compared to the non-gelatinous zooplankton, gelatinous zooplankton are especially difficult to study because of their complex life histories5, and their delicate tissues are easily damaged during capture and handling. Gelatinous zooplankton species are, therefore, notoriously difficult to culture in the laboratory and generally less studied compared to non-gelatinous species6.
Among gelatinous zooplankton groups, one abundant and of ecological importance in the world&#8217;s ocean are the Thaliaceans. Thaliaceans are a class of pelagic tunicates that include the orders Salpida, Pyrosomida, and Doliolida7. Doliolida, collectively referred to as doliolids, are small barrel-shaped free-swimming pelagic organisms that can reach high abundances in productive neritic regions of subtropical oceans. Doliolids are among the most abundant of all the zooplankton groups4,8. As suspension feeders, doliolids collect food particles from the water column by creating filter currents and capturing them on mucus nets9. Taxonomically, doliolids are classified in the phylum Urochordata10. Ancestral to the chordates, and in addition to their ecological significance as key components of marine pelagic systems, Thaliaceans are of significance to understanding the origins of colonial life history10,11 and the evolution of the chordates5,7,10,12,13,14.
The life history of doliolids is complex and contributes to the difficulty in culturing and sustaining them through their life cycle. A review of the doliolid life cycle and anatomy can be found in Godeaux et al.15. The doliolid life cycle, which involves an obligatory alternation between sexual and asexual life-history stages, is presented in Figure 1. Eggs and sperm are produced by the hermaphroditic gonozooids, the only solitary stage of the life cycle. Gonozooids release sperm to the water column and eggs are internally fertilized and released to develop into larvae. Larvae hatch and metamorphose into oozooids that can reach 1-2 mm. Presuming conducive environmental conditions and nutrition, oozooids become early nurses within 1-2 days at 20 &#176;C and initiate the colonial stages of the life cycle. Oozooids asexually produce buds on their ventral stolon. These buds leave the stolon and migrate to the dorsal cadophore where they line up in three paired rows. The central double rows become phorozooids and the outer two double rows become trophozooids. The latter provide food to both the nurse and the phorozooids16,17. The trophozooids supply the nurse with nutrition as she loses all internal organs. As the abundance of trophozooids increases, the size of the nurse can reach 15 mm in the laboratory. As the phorozooids grow, they increasingly ingest planktonic prey and reach ~ 1.5 mm in size prior to being released as individuals17. A single nurse may release &#62; 100 phorozooids during its lifespan18. After the phorozooids are released from the cadophore, they continue to grow and are the second colonial stage of the life cycle. Once they reach ~ 5 mm in size, each phorozooid develops a cluster of gonozooids on their ventral peduncle. These gonozooids can ingest particles when they reach ~1 mm in length. After the gonozooids have reached ~ 2 to 3 mm in size they are released from the phorozooid and become the only solitary stage of the life cycle. Once they reach ~ 6 mm in size, gonozooids become sexually mature17. Gonozooids can reach 9 mm or greater in length. Gonozooids are hermaphroditic, sperm is released intermittently while the fertilization of the eggs occurs internally16,17. When the gonozooid is &#8805; 6 mm in size, it releases up to 6 fertilized eggs. Successful culturing requires supporting the specific needs of each of these unique life history stages.
Due to the ecological and evolutionary significance of Thaliaceans, including doliolids, there is a need for the cultivation methodologies to advance the understanding of this organism&#8217;s unique biology, physiology, ecology, and evolutionary history19. Doliolids have considerable promise as experimental model organisms in developmental biology and functional genomics because they are transparent and likely have streamlined genomes20,21. The lack of reliable cultivation methods, however, impedes their usefulness as laboratory models. Although a handful of laboratories have published results based on cultured doliolids, to our knowledge cultivation approaches and detailed protocols have not been previously published. Based on years of experience, and trial and error cultivation attempts, the purpose of this study was to review experiences and to share protocols for the collection and cultivation of doliolids, specifically the species Dolioletta gegenbauri.

<table border="0" cellpadding="0" cellspacing="0" style="width:1860px;" width="1860">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:681px;">Algal culture tubes (55 mL sterile disposable glass culture tubes)</td>
			<td style="width:417px;">Any</td>
			<td style="width:167px;">NA</td>
			<td style="width:595px;">For algal cultures</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:681px;">Autoclave</td>
			<td style="width:417px;">Any</td>
			<td style="width:167px;">NA</td>
			<td>For sterilizing equipment and seawater for algal cultures</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:681px;">Beakers (2 L glass)</td>
			<td style="width:417px;">Any</td>
			<td style="width:167px;">NA</td>
			<td>For sorting diluted plankton net tow contents</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:681px;">Buckets (5 gallon, ~20L)</td>
			<td style="width:417px;">Any</td>
			<td style="width:167px;">NA</td>
			<td>For diluting contents of planton net tow - should be seawater conditioned before first use</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:681px;">Carboys (20 L)&#160;</td>
			<td style="width:417px;">Any</td>
			<td style="width:167px;">NA</td>
			<td>For storing seawater</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Doliolid glass culturing jar (1.9 L narrow mouth glass jar with cap)</td>
			<td>Qorpak</td>
			<td>GLC-01882</td>
			<td>Container for culture</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Doliolid glass culturing jar (3.8 L narrow mouth glass jar with cap)</td>
			<td>Qorpak</td>
			<td>GLC-01858</td>
			<td>Container for culture</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:681px;">Environmental Chamber (Temperature controlled enviromental chamber)</td>
			<td style="width:417px;">Any</td>
			<td style="width:167px;">NA</td>
			<td>To accommodate plankton wheel and culture maintenance</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:681px;">Filtration apparatus for 47 mm filters</td>
			<td style="width:417px;">Any</td>
			<td style="width:167px;">NA</td>
			<td>For filtering seawater for cultures</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Glass microfiber filters, 47 mm</td>
			<td>Whatman</td>
			<td>1825-047</td>
			<td>For filtering seawater for cultures</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Glass pipette (borosillicate glass pipette (glass tubing), OD 10mm, ID 8 mm, wall thickness 1mm)</td>
			<td>Science Company</td>
			<td>NC-10894</td>
			<td>Custom cut and edges polished</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:681px;">Hose clamps, stainless steel, #104 (178 mm)</td>
			<td style="width:417px;">Any</td>
			<td style="width:167px;">NA</td>
			<td>For holding culturing jars to the plankton wheel</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Isochrysis galbana strain CCMP1323</td>
			<td>National Center for Marine Algae and Microbiota (NCMA)</td>
			<td>strain CCMP1323</td>
			<td>For feeding doliolid cultures</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">L1 Media Kit, 50 L</td>
			<td>National Center for Marine Algae and Microbiota (NCMA)</td>
			<td>MKL150L</td>
			<td>For culturing algae</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:681px;">Lamp (Fluorescent table lamp with an adjustable arm)</td>
			<td style="width:417px;">Any</td>
			<td style="width:167px;">NA</td>
			<td>For illuminating doliolids in the jars and beakers</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:681px;">Lighted temperature controlled incubator</td>
			<td style="width:417px;">Any</td>
			<td style="width:167px;">NA</td>
			<td>For algal cultures</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:681px;">Micropipettes and sterile tips (0-20 &#181;l, 20-200 &#181;l, 200-1000&#160;&#181;l)</td>
			<td style="width:417px;">Any</td>
			<td style="width:167px;">NA</td>
			<td>For algal cultures</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Plankton Net (202 &#181;m 0.5 m, 5:1 length) with cod end ring and &#160;4 L aquarium cod-end</td>
			<td>Sea-Gear Corporation</td>
			<td>90-50x5-200-4A/BB</td>
			<td>For collecting living doliolids (see Figure 4)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:681px;">Plankton Wheel</td>
			<td style="width:417px;">NA</td>
			<td style="width:167px;">NA</td>
			<td>Custom built (see Figure 2)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Plastic wrap</td>
			<td>Any</td>
			<td>NA</td>
			<td>To cover inside of lid of doliolid culture jars</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Potassium Permanganate</td>
			<td>Fisher Scientific</td>
			<td>P279-500</td>
			<td>Reagent for cleaning jars and glassware</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Rhodomonas&#160;sp. strain CCMP740</td>
			<td>National Center for Marine Algae and Microbiota (NCMA)</td>
			<td>strain CCMP740</td>
			<td>For feeding doliolid cultures</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:681px;">Rubber Tubing</td>
			<td style="width:417px;">NA</td>
			<td style="width:167px;">NA</td>
			<td>For holding culturing jars to the plankton wheel (can be made from tygon tubing)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sodium Bisulfite</td>
			<td>Fisher Scientific</td>
			<td>S654-500</td>
			<td>Reagent for cleaning jars and glassware</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sodium Hydroxide</td>
			<td>Fisher Scientific</td>
			<td>BP359-212</td>
			<td>Reagent for cleaning jars and glassware</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:681px;">Sterile serological pipettes (1 mL, 5 mL, 10 mL, 25 mL)</td>
			<td style="width:417px;">Any</td>
			<td style="width:167px;">NA</td>
			<td>For algal cultures</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Thalassiosira weissflogii strain CCMP1051</td>
			<td>National Center for Marine Algae and Microbiota (NCMA)</td>
			<td>strain CCMP1051</td>
			<td>For feeding doliolid cultures</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:681px;">Tissue culture flasks (250 mL)</td>
			<td style="width:417px;">Any</td>
			<td style="width:167px;">NA</td>
			<td>For algal cultures</td>
		</tr>
	</tbody>
</table>

cultivation of the marine pelagic tunicate dolioletta gegenbauri (uljanin 1884) for experimental studies

Gelatinous zooplanktons play a crucial role in ocean ecosystems. However, it is generally difficult to investigate their physiology, growth, fecundity, and trophic interactions primarily due to methodological challenges, including the ability to culture them. This is particularly true for the doliolid, Dolioletta gegenbauri. D. gegenbauri commonly occurs in productive subtropical continental shelf systems worldwide, often at bloom concentrations capable of consuming a large fraction of daily primary production. In this study, we describe cultivation approaches for collecting, rearing, and maintaining D. gegenbauri for the purpose of conducting laboratory-based studies. D. gegenbauri and other doliolid species can be captured live using obliquely towed conical 202 &micro;m mesh plankton nets from a drifting ship. Cultures are most reliably established when water temperatures are below 21 &deg;C and are started from immature gonozooids, maturing phorozooids, and large nurses. Cultures can be maintained in rounded culture vessels on a slowly rotating plankton wheel and sustained on a diet of cultured algae in natural seawater for many generations. In addition to the ability to establish laboratory cultures of D. gegenbauri, we demonstrate that the collection condition, algae concentration, temperature, and exposure to naturally conditioned seawater are all critical to the culture establishment, growth, survival, and reproduction of D. gegenbauri.

Following the described procedures for collecting and culturing the doliolid, D. gegenbauri outlined in Figure 3, it is possible to maintain a culture of D. gegenbauri throughout its complex life history (Figure 1) and sustain it for many generations. Although cultivation of D. gegenbauri is described here, these procedures should also be relevant for the cultivation of other doliolid species.
Capturing heal...

Watch this Scientific Journal Video about Cultivation of the Marine Pelagic Tunicate Dolioletta gegenbauri Uljanin 1884 for Experimental Studies at JoVE.com

Cultivation of the Marine Pelagic Tunicate Dolioletta gegenbauri Uljanin 1884 for Experimental Studies

Doliolids, including the species Dolioletta gegenbauri, are small gelatinous marine zooplankton of ecological significance found on productive subcontinental shelf systems worldwide. The difficulty of culturing these delicate organisms limits their investigation. In this study, we describe cultivation approaches for collecting, rearing, and maintaining the doliolid Dolioletta gegenbauri.

Cultivation of the Marine Pelagic Tunicate Dolioletta gegenbauri (Uljanin 1884) for Experimental Studies

Gelatinous zooplanktons play a crucial role in ocean ecosystems. However, it is generally difficult to investigate their physiology, growth, fecundity, ...

Availability of culturable model organisms has been fundamental to the advancement in many fields of study. This protocol, to our knowledge, is the only approach available for culturing Doliolids. Reliable Doliolid culture technology provides a unique experimental model to study organisms that are important to some of the most productive regions of the ocean and that represent the earliest evolutionary ancestors of vertebrates.This technique is unique as it keeps the algal food particles and the organisms suspended in the water column without contact with the walls of the container as they experience in nature. This culturing method can be applied to the culturing of other small gelatinous and crustaceans or plankton species. Because Doliolids have a complex life cycle, understanding and recognizing the needs of each life stage is critical.Learning the life cycle and how to recognize and handle them takes a lot of practice. In our experience, the only way to learn this culturing technique is to see it and do it. Several other project participants including Erin Arneson, Nicholas Castalaine, Natalia Lopez, Lauren Lamboye, Briana Pierce, Arya Rodriguez-Santiago, and Terrell Scarborough also appeared briefly in this video.Before establishing and rearing Doliolid cultures in the laboratory, clean and sterilize 1.9 and 3.8 liter glass culture jars by immersing them in the sodium hydroxide potassium permanganate solution. Allow the jars to soak overnight. Then transfer the jars into the sodium bisulfite solution.Allow the jars to soak overnight. Next rinse the jars thoroughly with deionized water. Allow the jars to dry.To maintain stock cultures, use rigorous axenic culture techniques. Every two weeks transfer 0.5 milliliters of old senescent culture to 25 milliliters of fresh growth media in sterile 55 milliliter glass culture tubes. To prepare larger volumes of phytoplankton for feeding Doliolids, transfer four milliliters of the phytoplankton from axenic stocks into 500 milliliter plastic tissue culture flasks containing 200 milliliters of growth media to inoculate at one to 50 dilution.Incubate the culture in an environmental incubator or walk-in environmental chamber at 20 degrees Celsius with a 12 to 12 hour light-dark cycle under cool white light illumination of 65 to 85 microEinsteins per square meter. Lay culture flasks flat to maximize illumination. Gently swirl the culture daily.Head out to sea. To locate Doliolids on the continental shelf, deploy oceanographic instrument CTD for identifying water conditions conducive to the presence of Doliolids by profiling water temperature, salinity, and chlorophyll A fluorescence. Confirm the water conditions by conducting exploratory net tows with specialized plankton nets.Alternatively, use an in situ profiling imaging system to detect Doliolids. Now operate the winch to retrieve the CTD. The Niskin bottles mounted on the CTD rosette collected seawater from the site where Doliolids are located and at the depth containing the highest estimates of chlorophyll.Rinse three 22-liter buckets with seawater and fill with seawater to a little more than half full. Fill the net cod end completely with seawater and attach the cod end to the net. Deploy the net.Lower and raise the net through the water column, maintaining an oblique towing angle of 15 to 25 degrees and vertical deployment and retrieval speed not greater than 15 meters per minute. Once the net is on board gently transfer and divide the contents of the cod end into the plastic buckets each containing surface seawater collected from the site. Using a wide-bore glass pipette gently mix the contents of the beaker with the pipette using vertical and horizontal motions.Using the index finger, create capillary suction to capture and transfer Doliolids. Capture the Doliolids from mixed phytoplankton in the beaker. After the addition of Doliolids, add Rhodomonas culture into the jar to a final concentration of about five times 10 to the third to 10 to the fourth cells per milliliter.Check the color of the digestive tract of Doliolids. The red color determines the Doliolids are actively feeding. To prevent Doliolids from being trapped at the air-water interface, completely fill the jars with unfiltered, particle-rich seawater to avoid the head space.Place a piece of plastic wrap over the jar opening. Avoid creating air bubbles that can also damage the animals. Carefully screw the cap onto the jar and gently invert the jar to determine if bubbles are present.If bubbles are present, fill more seawater to remove them. After the jars are filled reseal with the lid and wipe the excess water from the outside of the jar. Mount each jar onto the plankton wheel by placing the jar on the vertical metal bars covered with rubber tubing and between a stainless steel hose clamp.Ensure that the back of the jar is cushioned against the rubber tubing. Adjust the screw to tighten the hose clamp around the jar. Allow the jars to rotate at 0.3 rpm to keep the Doliolids in suspension.After three days acclimation to the laboratory conditions transfer 100 to 150 milliliters of culture water from the jar to a sample container and measure the algae concentration using a Coulter counter. Based on the estimation of algal concentration, add sufficient algae to bring the concentration in the culture jar to 40 to 95 micrograms of carbon per liter. Use the particle counter to monitor algal concentrations after the Doliolids have been feeding to guide the decision of how frequently and how much algae to add to the cultures.Maintain phytoplankton concentrations in the culture jars between 40 to 95 micrograms of carbon per liter. Culturing Doliolids requires supporting them through their complicated life cycle. Developing larvae and oozooids and early nurses.Once a minimum of eight trophozooids are visible on the nurse's cataphor, transfer at least four nurses into a new culturing jar. Once the phorozooids reach three millimeters in size, reduce the number of animals in the jar. When the phorozooids become larger than five millimeters and have developed gonozooid clusters remove all but four phorozooids.This protocol provides an overview of a Dolioletta gegenbauri collection and cultivation approach. Algal clearance rates were similar at concentrations from 20 to 60 micrograms of carbon per liter and decreased as the food concentrations increased. Clearance rates increased proportionately over temperature ranges supportive of D.gegenbauri growth.Growth rates ranging from 0.1 to 0.7 millimeters per day as a function of temperature and food availability were observed. The cultivation of Doliolids depends on successfully replicating oceanic conditions and accommodating the needs of the animals throughout their complicated life cycle. Consequently, gentle handling of the animals during their capture, isolation, and husbandry is required.Food concentrations must be monitored frequently and adjusted. This is particularly true during the developing larvae and oozooid life stages. This method is specifically designed for the rearing of small zooplankton species at the base of the marine food web.This method will be valuable for example to investigate zooplankton responses to climate change. Since its development, this technique has paved the way for zooplankton ecologists to determine the laboratory-based feeding, growth, and reproduction rates of Doliolids. Additionally this method paved the way for revolutionary molecular-based investigations of the Doliolid diet in nature.I would like to remind you that the glass cleaning protocol involves reagents that are respiratory irritants and should be used in well-ventilated areas. Working at sea can also be hazardous so follow the ship safety rules.

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Research

JoVE Journal

Environment

A Noninvasive Method For In situ Determination of Mating Success in Female American Lobsters (Homarus americanus)

Despite being one of the most productive fisheries in the Northwest Atlantic, much remains unknown about the natural reproductive dynamics of American lobsters. Recent work in exploited crustacean populations (crabs and lobsters) suggests that there are circumstances where mature females are unable to achieve their full reproductive potential due to sperm limitation. To examine this possibility in different regions of the American lobster fishery, a reliable and noninvasive method was developed for sampling large numbers of female lobsters at sea. This method involves inserting a blunt-tipped needle into the female&#39;s seminal receptacle to determine the presence or absence of a sperm plug and to withdraw a sample that can be examined for the presence of sperm. A series of control studies were conducted at the dock and in the laboratory to test the reliability of this technique. These efforts entailed sampling 294 female lobsters to confirm that the presence of a sperm plug was a reliable indicator of sperm within the receptacle and thus, mating. This paper details the methodology and the results obtained from a subset of the total females sampled. Of the 230 female lobsters sampled from George&#39;s Bank and Cape Ann, MA (size range = 71-145 mm in carapace length), 90.3% were positive for sperm. Potential explanations for the absence of sperm in some females include: immaturity (lack of physiological maturity), breakdown of the sperm plug after being used to fertilize a clutch of eggs, and lack of mating activity. The surveys indicate that this technique for examining the mating success of female lobsters is a reliable proxy that can be used in the field to document reproductive activity in natural populations.

A Noninvasive Method For In situ Determination of Mating Success in Female American Lobsters Homarus americanus

Fishery-induced changes to exploited crustacean fisheries, such as the American lobster fishery, could potentially influence their reproductive dynamics, leading to a reduction in mating success. This study&#39;s goal was to develop a noninvasive method for ascertaining the mating success of female lobsters that may be physiologically or functionally mature.

Despite being one of the most productive fisheries in the Northwest Atlantic, much remains unknown about the natural reproductive dynamics of American ...

A Fish-feeding Laboratory Bioassay to Assess the Antipredatory Activity of Secondary Metabolites from the Tissues of Marine Organisms

Marine chemical ecology is a young discipline, having emerged from the collaboration of natural products chemists and marine ecologists in the 1980s with the goal of examining the ecological functions of secondary metabolites from the tissues of marine organisms. The result has been a progression of protocols that have increasingly refined the ecological relevance of the experimental approach. Here we present the most up-to-date version of a fish-feeding laboratory bioassay that enables investigators to assess the antipredatory activity of secondary metabolites from the tissues of marine organisms. Organic metabolites of all polarities are exhaustively extracted from the tissue of the target organism and reconstituted at natural concentrations in a nutritionally appropriate food matrix. Experimental food pellets are presented to a generalist predator in laboratory feeding assays to assess the antipredatory activity of the extract. The procedure described herein uses the bluehead, Thalassoma bifasciatum, to test the palatability of Caribbean marine invertebrates; however, the design may be readily adapted to other systems. Results obtained using this laboratory assay are an important prelude to field experiments that rely on the feeding responses of a full complement of potential predators. Additionally, this bioassay can be used to direct the isolation of feeding-deterrent metabolites through bioassay-guided fractionation. This feeding bioassay has advanced our understanding of the factors that control the distribution and abundance of marine invertebrates on Caribbean coral reefs and may inform investigations in diverse fields of inquiry, including pharmacology, biotechnology, and evolutionary ecology.

This bioassay employs a model predatory fish to assess the presence of feeding-deterrent metabolites from organic extracts of the tissues of marine organisms at natural concentrations using a nutritionally comparable food matrix.

Marine chemical ecology is a young discipline, having emerged from the collaboration of natural products chemists and marine ecologists in the 1980s with ...

Clean Sampling and Analysis of River and Estuarine Waters for Trace Metal Studies

Most of the trace metal concentrations in ambient waters obtained a few decades ago have been considered unreliable owing to the lack of contamination control. Developments of some techniques aiming to reduce trace metal contamination in the last couple of decades have resulted in concentrations reported now being orders of magnitude lower than those in the past. These low concentrations often necessitate preconcentration of water samples prior to instrumental analysis of samples. Since contamination can appear in all phases of trace metal analyses, including sample collection (and during preparation of sampling containers), storage and handling, pretreatments, and instrumental analysis, specific care needs to be taken in order to reduce contamination levels at all steps. The effort to develop and utilize "clean techniques" in trace metal studies allows scientists to investigate trace metal distributions and chemical and biological behavior in greater details. This advancement also provides the required accuracy and precision of trace metal data allowing for environmental conditions to be related to trace metal concentrations in aquatic environments.
This protocol that is presented here details needed materials for sample preparation, sample collection, sample pretreatment including preconcentration, and instrumental analysis. By reducing contamination throughout all phases mentioned above for trace metal analysis, much lower detection limits and thus accuracy can be achieved. The effectiveness of "clean techniques" is further demonstrated using low field blanks and good recoveries for standard reference material. The data quality that can be obtained thus enables the assessment of trace metal distributions and their relationships to environmental parameters.

Special care using "clean techniques" is required to properly collect and process water samples for trace metal studies in aquatic environments. A protocol for sampling, processing, and analytical procedures with the aim of obtaining reliable environmental monitoring data and results with high sensitivity for detailed trace metal studies is presented.

Most of the trace metal concentrations in ambient waters obtained a few decades ago have been considered unreliable owing to the lack of contamination ...

Experimental Protocol for Biodiesel Production with Isolation of Alkenones as Coproducts from Commercial Isochrysis Algal Biomass

The need to replace petroleum fuels with alternatives from renewable and more environmentally sustainable sources is of growing importance. Biomass-derived biofuels have gained considerable attention in this regard, however first generation biofuels from edible crops like corn ethanol or soybean biodiesel have generally fallen out of favor. There is thus great interest in the development of methods for the production of liquid fuels from domestic and superior non-edible sources. Here we describe a detailed procedure for the production of a purified biodiesel from the marine microalgae Isochrysis. Additionally, a unique suite of lipids known as polyunsaturated long-chain alkenones are isolated in parallel as potentially valuable coproducts to offset the cost of biodiesel production. Multi-kilogram quantities of Isochrysis are purchased from two commercial sources, one as a wet paste (80% water) that is first dried prior to processing, and the other a dry milled powder (95% dry). Lipids are extracted with hexanes in a Soxhlet apparatus to produce an algal oil (&#34;hexane algal oil&#34;) containing both traditional fats (i.e., triglycerides, 46-60% w/w) and alkenones (16-25% w/w). Saponification of the triglycerides in the algal oil allows for separation of the resulting free fatty acids (FFAs) from alkenone-containing neutral lipids. FFAs are then converted to biodiesel (i.e., fatty acid methyl esters, FAMEs) by acid-catalyzed esterification while alkenones are isolated and purified from the neutral lipids by crystallization. We demonstrate that biodiesel from both commercial Isochrysis biomasses have similar but not identical FAME profiles, characterized by elevated polyunsaturated fatty acid contents (approximately 40% w/w). Yields of biodiesel were consistently higher when starting from the Isochrysis wet paste (12% w/w vs. 7% w/w), which can be traced to lower amounts of hexane algal oil obtained from the powdered Isochrysis product.

Experimental Protocol for Biodiesel Production with Isolation of Alkenones as Coproducts from Commercial Isochrysis Algal Biomass

Detailed methods are presented for the production of biodiesel along with the co-isolation of alkenones as valuable coproducts from commercial Isochrysis microalgae.

The need to replace petroleum fuels with alternatives from renewable and more environmentally sustainable sources is of growing importance. ...

VacuSIP, an Improved InEx Method for In Situ Measurement of Particulate and Dissolved Compounds Processed by Active Suspension Feeders

Benthic suspension feeders play essential roles in the functioning of marine ecosystems. By filtering large volumes of water, removing plankton and detritus, and excreting particulate and dissolved compounds, they serve as important agents for benthic-pelagic coupling. Accurately measuring the compounds removed and excreted by suspension feeders (such as sponges, ascidians, polychaetes, bivalves) is crucial for the study of their physiology, metabolism, and feeding ecology, and is fundamental to determine the ecological relevance of the nutrient fluxes mediated by these organisms. However, the assessment of the rate by which suspension feeders process particulate and dissolved compounds in nature is restricted by the limitations of the currently available methodologies. Our goal was to develop a simple, reliable, and non-intrusive method that would allow clean and controlled water sampling from a specific point, such as the excurrent aperture of benthic suspension feeders, in situ. Our method allows simultaneous sampling of inhaled and exhaled water of the studied organism by using minute tubes installed on a custom-built manipulator device and carefully positioned inside the exhalant orifice of the sampled organism. Piercing a septum on the collecting vessel with a syringe needle attached to the distal end of each tube allows the external pressure to slowly force the sampled water into the vessel through the sampling tube. The slow and controlled sampling rate allows integrating the inherent patchiness in the water while ensuring contamination free sampling. We provide recommendations for the most suitable filtering devices, collection vessel, and storing procedures for the analyses of different particulate and dissolved compounds. The VacuSIP system offers a reliable method for the quantification of undisturbed suspension feeder metabolism in natural conditions that is cheap and easy to learn and apply to assess the physiology and functional role of filter feeders in different ecosystems.

VacuSIP, an Improved InEx Method for In Situ Measurement of Particulate and Dissolved Compounds Processed by Active Suspension Feeders

We introduce the VacuSIP, a simple, non-intrusive, and reliable method for clean and accurate point sampling of water. The system was developed and evaluated for the simultaneous collection of the water inhaled and exhaled by benthic suspension feeders in situ, to cleanly measure removal and excretion of particulate and dissolved compounds.

Benthic suspension feeders play essential roles in the functioning of marine ecosystems. By filtering large volumes of water, removing plankton and ...

Ecotoxicological Method with Marine Bacteria Vibrio anguillarum to Evaluate the Acute Toxicity of Environmental Contaminants

Bacteria are an important component of the ecosystem, and microbial community alterations can have a significant effect on biogeochemical cycling and food webs. Toxicity testing based on microorganisms are widely used because they are relatively quick, reproducible, cheap, and are not associated with ethical issues. Here, we describe an ecotoxicological method to evaluate the biological response of the marine bacterium Vibrio anguillarum. This method assesses the acute toxicity of chemical compounds, including new contaminants such as nanoparticles, as well as environmental samples. The endpoint is the reduction of bacterial culturability (i.e., the capability to replicate and form colonies) due to exposure to a toxicant. This reduction can be generally referred to as mortality. The test allows for the determination of the LC50, the concentration that causes a 50% decrease of bacteria actively replicating and forming colonies, after a 6 h exposure. The culturable bacteria are counted in terms of colony forming units (CFU), and the &#34;mortality&#34; is evaluated and compared to the control. In this work, the toxicity of copper sulphate (CuSO4) was evaluated. A clear dose-response relationship was observed, with a mean LC50 of 1.13 mg/L, after three independent tests. This protocol, compared to existing methods with microorganisms, is applicable in a wider range of salinity and has no limitations for colored/turbid samples. It uses saline solution as the exposure medium, avoiding any possible interferences of growth medium with the investigated contaminants. The LC50 calculation facilitates comparisons with other bioassays commonly applied to ecotoxicological assessments of the marine environment.

Ecotoxicological Method with Marine Bacteria Vibrio anguillarum to Evaluate the Acute Toxicity of Environmental Contaminants

This work describes a new protocol to assess the ecotoxicity of pollutants, including emerging contaminants such as nanomaterials, using the marine bacterium Vibrio anguillarum. This method allows for the determination of the LC50, or mortality, the concentration that causes a 50% decrease in bacteria culturability, after a 6 h exposure.

Bacteria are an important component of the ecosystem, and microbial community alterations can have a significant effect on biogeochemical cycling and food ...

Vegetated Treatment Systems for Removing Contaminants Associated with Surface Water Toxicity in Agriculture and Urban Runoff

Urban stormwater and agriculture irrigation runoff contain a complex mixture of contaminants that are often toxic to adjacent receiving waters. Runoff may be treated with simple systems designed to promote sorption of contaminants to vegetation and soils and promote infiltration. Two example systems are described: a bioswale treatment system for urban stormwater treatment, and a vegetated drainage ditch for treating agriculture irrigation runoff. Both have similar attributes that reduce contaminant loading in runoff: vegetation that results in sorption of the contaminants to the soil and plant surfaces, and water infiltration. These systems may also include the integration of granulated activated carbon as a polishing step to remove residual contaminants. Implementation of these systems in agriculture and urban watersheds requires system monitoring to verify treatment efficacy. This includes chemical monitoring for specific contaminants responsible for toxicity. The current paper emphasizes monitoring of current use pesticides since these are responsible for surface water toxicity to aquatic invertebrates.

This article summarizes the design attributes and the effectiveness of treatment systems that treat urban stormwater and agriculture irrigation runoff to remove pesticides and other contaminants associated with aquatic toxicity.

Urban stormwater and agriculture irrigation runoff contain a complex mixture of contaminants that are often toxic to adjacent receiving waters. Runoff may ...

Extraction of Organochlorine Pesticides from Plastic Pellets and Plastic Type Analysis

Plastic resin pellets, categorized as microplastics (&#8804;5 mm in diameter), are small granules that can be unintentionally released to the environment during manufacturing and transport. Because of their environmental persistence, they are widely distributed in the oceans and on beaches all over the world. They can act as a vector of potentially toxic organic compounds (e.g., polychlorinated biphenyls) and might consequently negatively affect marine organisms. Their possible impacts along the food chain are not yet well understood. In order to assess the hazards associated with the occurrence of plastic pellets in the marine environment, it is necessary to develop methodologies that allow for rapid determination of associated organic contaminant levels. The present protocol describes the different steps required for sampling resin pellets, analyzing adsorbed organochlorine pesticides (OCPs) and identifying the plastic type. The focus is on the extraction of OCPs from plastic pellets by means of a pressurized fluid extractor (PFE) and on the polymer chemical analysis applying Fourier Transform-InfraRed (FT-IR) spectroscopy. The developed methodology focuses on 11 OCPs and related compounds, including dichlorodiphenyltrichloroethane (DDT) and its two main metabolites, lindane and two production isomers, as well as the two biologically active isomers of technical endosulfan. This protocol constitutes a simple and rapid alternative to existing methodology for evaluating the concentration of organic contaminants adsorbed on plastic pieces.

Microplastics act as vector of potentially toxic organic contaminants with unpredictable effects. This protocol describes an alternative methodology for assessing the levels of organochlorine pesticides adsorbed on plastic pellets and identifying the polymer chemical structure. The focus is on pressurized fluid extraction and attenuated total reflectance Fourier transform infrared spectroscopy.

Plastic resin pellets, categorized as microplastics (&#8804;5 mm in diameter), are small granules that can be unintentionally released to the environment ...

Development of New Methods for Quantifying Fish Density Using Underwater Stereo-video Tools

The use of video camera systems in ecological studies of fish continues to gain traction as a viable, non-extractive method of measuring fish lengths and estimating fish abundance. We developed and implemented a rotating stereo-video camera tool that covers a full 360 degrees of sampling, which maximizes sampling effort compared to stationary camera tools. A variety of studies have detailed the ability of static, stereo-camera systems to obtain highly accurate and precise measurements of fish; the focus here was on the development of methodological approaches to quantify fish density using rotating camera systems. The first approach was to develop a modification of the metric MaxN, which typically is a conservative count of the minimum number of fish observed on a given camera survey. We redefine MaxN to be the maximum number of fish observed in any given rotation of the camera system. When precautions are taken to avoid double counting, this method for MaxN may more accurately reflect true abundance than that obtained from a fixed camera. Secondly, because stereo-video allows fish to be mapped in three-dimensional space, precise estimates of the distance-from-camera can be obtained for each fish. By using the 95% percentile of the observed distance from camera to establish species-specific areas surveyed, we account for differences in detectability among species while avoiding diluting density estimates by using the maximum distance a species was observed. Accounting for this range of detectability is critical to accurately estimate fish abundances. This methodology will facilitate the integration of rotating stereo-video tools in both applied science and management contexts.

We describe a new method for counting fishes, and estimating relative abundance (MaxN) and fish density using rotating stereo-video camera systems. We also demonstrate how to use distance from camera (Z distance) to estimate species-specific detectability.

The use of video camera systems in ecological studies of fish continues to gain traction as a viable, non-extractive method of measuring fish lengths and ...

Methods for Image-based Surveys of Benthic Macroinvertebrates and Their Habitat Exemplified by the Drop Camera Survey for the Atlantic Sea Scallop

Underwater imaging has long been used in the field of marine ecology but decreasing costs of high-resolution cameras and data storage have made the approach more practical than in the past. Image-based surveys allow for initial samples to be revisited and are non-invasive compared to traditional survey methods that typically involve nets or dredges. Protocols for image-based surveys can vary greatly but should be driven by target species behavior and survey objectives. To demonstrate this, we describe our most recent methods for an Atlantic sea scallop (Placopecten magellanicus) drop camera survey to provide a procedural example and representative results. The procedure is divided into three critical steps that include survey design, data collection, and data products. The influence of scallop behavior and the survey goal of providing an independent assessment of the U.S. sea scallop resource on the survey procedure are then discussed in the context of generalizing the method. Overall, the broad applicability and flexibility of the University of Massachusetts Dartmouth School for Marine Science and Technology (SMAST) drop camera survey demonstrates the method could be generalized and applied to a variety of sessile invertebrates or habitat focused research.

Image based surveying is an increasingly practical, non-invasive method to sample the marine environment. We present the protocol of a drop camera survey that estimates the abundance and distribution of the Atlantic sea scallop (Placopecten magellanicus). We discuss how this protocol can be generalized for application to other benthic macroinvertebrates.

Underwater imaging has long been used in the field of marine ecology but decreasing costs of high-resolution cameras and data storage have made the ...