scholarly journals Deformities in larvae and juvenile European lobster (<i>Homarus gammarus</i>) exposed to lower pH at two different temperatures

2013 ◽  
Vol 10 (5) ◽  
pp. 7579-7615 ◽  
Author(s):  
A.-L. Agnalt ◽  
E. S. Grefsrud ◽  
E. Farestveit ◽  
M. Larsen ◽  
F. Keulder

Abstract. Trends of increasing temperatures and ocean acidification are expected to influence benthic marine resources, especially calcifying organisms. The European lobster (Homarus gammarus) is among those species at risk. A project was initiated in 2011 aiming to investigate long-term synergistic effects of temperature and projected increases in ocean acidification on the life cycle of lobster. Larvae were exposed to pCO2 levels of ambient water (water intake at 90 m depth, tentatively of 380 μatm pCO2), 727 and 1217 μatm pCO2, at temperatures 10 and 18 °C. Long-term exposure lasted until 5 months of age. Thereafter the surviving juveniles were transferred to ambient water at 14 °C. At 18 °C the development from Stage 1 to 4 lasted from 14 to 16 days, as predicted under normal pH values. Growth was very slow at 10 °C and resulted in only two larvae reaching Stage 4 in the ambient treatment. There were no significant differences in carapace length at the various larval stages between the different treatments, but there were differences in total length and dry weight at Stage 1 at 10 °C, Stage 2 at both temperatures, producing larvae slightly larger in size and lighter by dry weight in the exposed treatments. Stage 3 larvae raised in 18 °C and 1217 μatm pCO2 were also larger in size and heavier by dry weight compared with 727 μatm. Unfortunate circumstances precluded a full comparison across stages and treatment. Deformities were however observed in both larvae and juveniles. At 10 °C, about 20% of the larvae exposed to elevated pCO2were deformed, compared with 0% in larvae raised in pH above 8.0. At 18 °C and in high pCO2 treatment, 31.5% of the larvae were deformed. Occurrence of deformities after 5 months of exposure was 33 and 44% in juveniles raised in ambient and low pCO2, respectively, and 20% in juveniles exposed to high pCO2. Some of the deformities will possibly affect the ability to find food, sexual partner (walking legs, claw and antenna), respiration (carapace), and ability to swim (tail-fan damages).

2013 ◽  
Vol 10 (12) ◽  
pp. 7883-7895 ◽  
Author(s):  
A.-L. Agnalt ◽  
E. S. Grefsrud ◽  
E. Farestveit ◽  
M. Larsen ◽  
F. Keulder

Abstract. The ongoing warming and acidification of the world's oceans are expected to influence the marine ecosystems, including benthic marine resources. Ocean acidification may especially have an impact on calcifying organisms, and the European lobster (Homarus gammarus) is among those species at risk. A project was initiated in 2011 aiming to investigate long-term effects of ocean acidification on the early life-cycle of lobster under two temperatures. Larvae were exposed to pCO2 levels of ambient water (water intake at 90 m depth), medium 750 (pH = 7.79) and high 1200 μatm pCO2 (pH = 7.62) at temperatures 10 and 18 °C. The water parameters in ambient water did not stay stable and were very low towards the end of the experiment in the larval phase at 10 °C,with pH between 7.83 and 7.90. At 18°, pH in ambient treatment was even lower, between 7.76 and 7.83, i.e. close to medium pCO2 treatment. Long-term exposure lasted 5 months. At 18 °C the development from stage 1 to 4 lasted 14 to 16 days, as predicted under optimal water conditions. Growth was very slow at 10 °C and resulted in three larvae reaching stage 4 in high pCO2 treatment only. There were no clear effects of pCO2 treatment, on either carapace length or dry weight. However, deformities were observed in both larvae and juveniles. The proportion of larvae with deformities increased with increasing pCO2 exposure, independent of temperature. In the medium treatment about 23% were deformed, and in the high treatment about 43% were deformed. None of the larvae exposed to water of pH >7.9 developed deformities. Curled carapace was the most common deformity found in larvae raised in medium pCO2 treatment, irrespective of temperature, but damages in the tail fan occurred in addition to a bent rostrum. Curled carapace was the only deformity found in high pCO2 treatment at both temperatures. Occurrence of deformities after five months of exposure was 33 and 44% in juveniles raised in ambient and low pCO2 levels, respectively, and 21% in juveniles exposed to high pCO2. Deformed claws were most often found in ambient and medium treatment (56%, followed by stiff/twisted walking legs (39%) and puffy carapace (39%). In comparison, at high pCO2 levels 71% of the deformed juveniles had developed a puffy carapace. Overall, about half of the deformed juveniles from the ambient and medium pCO2 treatment displayed two or three different abnormalities; 70% had multiple deformities in the high pCO2 treatment. Some of the deformities in the juveniles may affect respiration (carapace), the ability to find food, or sexual partners (walking legs, claw and antenna), and ability to swim (tail-fan damages).


2015 ◽  
Vol 73 (3) ◽  
pp. 704-714 ◽  
Author(s):  
Jan Vicente ◽  
Nyssa J. Silbiger ◽  
Billie A. Beckley ◽  
Charles W. Raczkowski ◽  
Russell T. Hill

Abstract Siliceous sponges have survived pre-historical mass extinction events caused by ocean acidification and recent studies suggest that siliceous sponges will continue to resist predicted increases in ocean acidity. In this study, we monitored silica biomineralization in the Hawaiian sponge Mycale grandis under predicted pCO2 and sea surface temperature scenarios for 2100. Our goal was to determine if spicule biomineralization was enhanced or repressed by ocean acidification and thermal stress by monitoring silica uptake rates during short-term (48 h) experiments and comparing biomineralized tissue ratios before and after a long-term (26 d) experiment. In the short-term experiment, we found that silica uptake rates were not impacted by high pCO2 (1050 µatm), warmer temperatures (27°C), or combined high pCO2 with warmer temperature (1119 µatm; 27°C) treatments. The long-term exposure experiments revealed no effect on survival or growth rates of M. grandis to high pCO2 (1198 µatm), warmer temperatures (25.6°C), or combined high pCO2 with warmer temperature (1225 µatm, 25.7°C) treatments, indicating that M. grandis will continue to prosper under predicted increases in pCO2 and sea surface temperature. However, ash-free dry weight to dry weight ratios, subtylostyle lengths, and silicified weight to dry weight ratios decreased under conditions of high pCO2 and combined pCO2 warmer temperature treatments. Our results show that rising ocean acidity and temperature have marginal negative effects on spicule biomineralization and will not affect sponge survival rates of M. grandis.


2001 ◽  
Vol 49 (8) ◽  
pp. 1013-1023 ◽  
Author(s):  
Jean-Hervé Lignot ◽  
Guy Charmantier

We examined the ontogeny of the osmoregulatory sites of the branchial cavity in embryonic and early postembryonic stages of the European lobster Homarus gammarus through transmission electron microscopy, immunofluorescence microscopy, and immunogold electron microscopy using a monoclonal antibody IgGα5 raised against the avian α-subunit of the Na+,K+-ATPase. In mid-late embryos, Na+,K+-ATPase was located along the pleurites and within the epipodite buds. In late embryos just before hatching, the enzyme was confined to the epipodite epithelia. After hatching, slight differentiations of ionocytes occured in the epipodites of larval stages. Na+,K+-ATPase was also located in the ionocytes of the epipodites of larvae exposed to seawater (35.0‰) and to dilute seawater (22.1 ‰). After metamorphosis, the inner-side branchiostegite epithelium appeared as an additional site of enzyme location in postlarvae held in dilute seawater. Within the ionocytes, Na+,K+-ATP-ase was mostly located along the basolateral infoldings. These observations are discussed in relation to the physiological shift from osmoconforming larvae to slightly hyper-regulating (in dilute seawater) postmetamorphic stages. The acquisition of the ability to hyper-osmo-regulate probably originates from the differentiation, on the epipodites and mainly along the branchiostegites, of ionocytes that are the site of ion pumping as evidenced by the location of Na+,K+-ATPase. (J Histochem Cytochem 49:1013–1023, 2001)


2015 ◽  
Vol 66 (4) ◽  
pp. 385
Author(s):  
Ronny Steen ◽  
Sondre Ski

Long-term studies of subtidal marine animals in the wild are a demanding enterprise. Traditionally, data collection has been limited to direct observations during SCUBA diving. In the past decade, video technology has improved rapidly and behavioural monitoring of marine organisms has successfully been conducted by using modern video-recording equipment. Here, we describe a video-monitoring system that employs video motion detection (VMD) and describe its use with the European lobster (Homarus gammarus). There is a shortage of detailed information on lobster behaviour in the wild, with virtually no published data on the fine-scale behaviour of the European lobster under natural conditions. This dearth of information reflects the difficulties in observing behaviour in nocturnal marine animals. Here, we explore whether a remote video-surveillance system is suitable for long-term monitoring of European lobsters inhabiting an artificial cavity in a natural habitat. From the video recordings, we were able to register diel cavity use and categorise behavioural elements such as resting, feeding, burrowing and substrate moving, self-cleaning, burrow occupancy and interactions among individuals. We propose that this novel system will contribute to more efficient data sampling of lobsters and facilitate non-invasive, long-term behavioural studies of other marine and freshwater animals.


Author(s):  
Clara Coll-Lladó ◽  
Felix Mittermayer ◽  
Paul Brian Webb ◽  
Nicola Allison ◽  
Catriona Clemmesen ◽  
...  

AbstractTo date the study of ocean acidification on fish otolith formation has been mainly focused on larval and juvenile stages. In the present pilot study, wild-captured adult Atlantic cod (Gadus morhua) were exposed to two different levels of pCO2, 422µatm (ambient, low pCO2) or 1091µatm (high pCO2), for a period of 30 weeks (from mid-October to early April 2014–2015) in order to study the effects on otolith size, shape and CaCO3 crystallization amongst other biological parameters. We found that otoliths from cod exposed to high pCO2 were slightly smaller (− 3.4% in length; − 3.3% in perimeter), rounder (− 2.9% circularity and + 4% roundness) but heavier (+ 5%) than the low pCO2 group. Interestingly, there were different effects in males and females; for instance, male cods exposed to high pCO2 exhibited significant changes in circularity (− 3%) and roundness (+ 4%) compared to the low pCO2 males, but without significant changes on otolith dimensions, while females exposed to high pCO2 had smaller otoliths as shown for length (− 5.6%), width (− 2%), perimeter (− 3.5%) and area (− 4.8%). Furthermore, while the majority of the otoliths analysed showed normal aragonite deposition, 10% of fish exposed to 1091µatm of pCO2 had an abnormal accretion of calcite, suggesting a shift on calcium carbonate polymorph crystallization in some individuals under high pCO2 conditions. Our preliminary results indicate that high levels of pCO2 in adult Atlantic cod might affect otolith growth in a gender-specific way. Our findings reveal that otoliths from adult cod are affected by ocean acidification, and we believe that the present study will prompt further research into this currently under-explored area.


2014 ◽  
Vol 11 (6) ◽  
pp. 1581-1597 ◽  
Author(s):  
K. Haynert ◽  
J. Schönfeld ◽  
R. Schiebel ◽  
B. Wilson ◽  
J. Thomsen

Abstract. Calcifying foraminifera are expected to be endangered by ocean acidification; however, the response of a complete community kept in natural sediment and over multiple generations under controlled laboratory conditions has not been constrained to date. During 6 months of incubation, foraminiferal assemblages were kept and treated in natural sediment with pCO2-enriched seawater of 430, 907, 1865 and 3247 μatm pCO2. The fauna was dominated by Ammonia aomoriensis and Elphidium species, whereas agglutinated species were rare. After 6 months of incubation, pore water alkalinity was much higher in comparison to the overlying seawater. Consequently, the saturation state of Ωcalc was much higher in the sediment than in the water column in nearly all pCO2 treatments and remained close to saturation. As a result, the life cycle (population density, growth and reproduction) of living assemblages varied markedly during the experimental period, but was largely unaffected by the pCO2 treatments applied. According to the size–frequency distribution, we conclude that foraminifera start reproduction at a diameter of 250 μm. Mortality of living Ammonia aomoriensis was unaffected, whereas size of large and dead tests decreased with elevated pCO2 from 285 μm (pCO2 from 430 to 1865 μatm) to 258 μm (pCO2 3247 μatm). The total organic content of living Ammonia aomoriensis has been determined to be 4.3% of CaCO3 weight. Living individuals had a calcium carbonate production rate of 0.47 g m−2 a−1, whereas dead empty tests accumulated a rate of 0.27 g m−2 a−1. Although Ωcalc was close to 1, approximately 30% of the empty tests of Ammonia aomoriensis showed dissolution features at high pCO2 of 3247 μatm during the last 2 months of incubation. In contrast, tests of the subdominant species, Elphidium incertum, stayed intact. Our results emphasize that the sensitivity to ocean acidification of the endobenthic foraminifera Ammonia aomoriensis in their natural sediment habitat is much lower compared to the experimental response of specimens isolated from the sediment.


2009 ◽  
Vol 6 (8) ◽  
pp. 1747-1754 ◽  
Author(s):  
K. E. Arnold ◽  
H. S. Findlay ◽  
J. I. Spicer ◽  
C. L. Daniels ◽  
D. Boothroyd

Abstract. Oceanic uptake of anthropogenic CO2 results in a reduction in pH termed "Ocean Acidification" (OA). Comparatively little attention has been given to the effect of OA on the early life history stages of marine animals. Consequently, we investigated the effect of culture in CO2-acidified sea water (approx. 1200 ppm, i.e. average values predicted using IPCC 2007 A1F1 emissions scenarios for year 2100) on early larval stages of an economically important crustacean, the European lobster Homarus gammarus. Culture in CO2-acidified sea water did not significantly affect carapace length of H. gammarus. However, there was a reduction in carapace mass during the final stage of larval development in CO2-acidified sea water. This co-occurred with a reduction in exoskeletal mineral (calcium and magnesium) content of the carapace. As the control and high CO2 treatments were not undersaturated with respect to any of the calcium carbonate polymorphs measured, the physiological alterations we record are most likely the result of acidosis or hypercapnia interfering with normal homeostatic function, and not a direct impact on the carbonate supply-side of calcification per se. Thus despite there being no observed effect on survival, carapace length, or zoeal progression, OA related (indirect) disruption of calcification and carapace mass might still adversely affect the competitive fitness and recruitment success of larval lobsters with serious consequences for population dynamics and marine ecosystem function.


2013 ◽  
Vol 70 (3) ◽  
pp. 532-539 ◽  
Author(s):  
Vidar Øresland ◽  
Mats Ulmestrand

Abstract Øresland, V., and Ulmestrand, M. 2013. European lobster subpopulations from limited adult movements and larval retention. – ICES Journal of Marine Science, 70: 532–539. Adults and larvae of the European lobster, Homarus gammarus, were studied within and around the Swedish Kåvra lobster reserve (2.2 km2). Tagging of 4016 lobsters within the reserve showed that the lobsters have limited movement out of the reserve. Only 58 lobsters (1.4% of all tagged lobsters) were recaptured ≥1 km from the reserve and 5658 recaptures were obtained inside the reserve. Light trap catches showed that stage 1 larvae had a peak occurrence during <2 weeks, in early August, 2007–2009. The mean depth distribution of stage 1 larvae was 16 m and very few larvae were found in the low saline surface layer. No later stages were found in horizontal net tows. The lobsters inside the reserve provided stage 1 larvae to the nearby area. A persistent retention of water masses was found at 16-m depth (below the sharp halocline) in the area (16 km2) around the reserve using IMR GPS Current Drifters. In sharp contrast, surface drifters showed strong offshore and inshore movements. The Swedish archipelago might harbour many lobster and other decapod subpopulations, if the larval stages occur in a large proportion below the sharp halocline and if adult movements are limited.


2009 ◽  
Vol 6 (2) ◽  
pp. 3087-3107 ◽  
Author(s):  
K. E. Arnold ◽  
H. S. Findlay ◽  
J. I. Spicer ◽  
C. L. Daniels ◽  
D. Boothroyd

Abstract. Oceanic uptake of anthropogenic CO2 results in a reduction in pH termed "Ocean Acidification" (OA). Comparatively little attention has been given to the effect of OA on the early life history stages of marine animals. Consequently, we investigated the effect of culture in CO2-acidified sea water (approx. 1200 ppm, i.e. average values predicted using IPCC 2007 A1F1 emissions scenarios for year 2100) on early larval stages of an economically important crustacean, the European lobster Homarus gammarus. Culture in CO2-acidified sea water did not significantly affect carapace length or development of H. gammarus. However, there was a reduction in carapace mass during the final stage of larval development in CO2-acidified sea water. This co-occurred with a reduction in exoskeletal mineral (calcium and magnesium) content of the carapace. As the control and high CO2 treatments were not undersaturated with respect to any of the calcium carbonate polymorphs measured, the physiological alterations we record are most likely the result of acidosis or hypercapnia interfering with normal homeostatic function, and not a direct impact on the carbonate supply-side of calcification per se. Thus despite there being no observed effect on survival, carapace length, or zoeal progression, OA related (indirect) disruption of calcification and carapace mass might still adversely affect the competitive fitness and recruitment success of larval lobsters with serious consequences for population dynamics and marine ecosystem function.


2014 ◽  
Vol 65 (12) ◽  
pp. 1094 ◽  
Author(s):  
Ronny Steen ◽  
Sondre Ski

Long-term studies of subtidal marine animals in the wild are a demanding enterprise. Traditionally, data collection has been limited to direct observations during SCUBA diving. In the past decade, video technology has improved rapidly and behavioural monitoring of marine organisms has successfully been conducted by using modern video-recording equipment. Here, we describe a video-monitoring system that employs video motion detection (VMD) and describe its use with the European lobster (Homarus gammarus). There is a shortage of detailed information on lobster behaviour in the wild, with virtually no published data on the fine-scale behaviour of the European lobster under natural conditions. This dearth of information reflects the difficulties in observing behaviour in nocturnal marine animals. Here, we explore whether a remote video-surveillance system is suitable for long-term monitoring of European lobsters inhabiting an artificial cavity in a natural habitat. From the video recordings, we were able to register diel cavity use and categorise behavioural elements such as resting, feeding, burrowing and substrate moving, self-cleaning, burrow occupancy and interactions among individuals. We propose that this novel system will contribute to more efficient data sampling of lobsters and facilitate non-invasive, long-term behavioural studies of other marine and freshwater animals.


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