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Hodge Dillon posted an update 6 months, 3 weeks ago
Spiny lobster post-larvae undertake an extensive migration from the open ocean to the coast, during which time their swimming is fueled solely by energy reserves accumulated through their preceding larval phase. We assessed the influence of future ocean temperatures on the swimming behavior and energy use of migrating post-larvae of Sagmariasus verreauxi, by experimentally swimming post-larvae for up to 6 days at three temperatures and measuring the lipid and protein used, and observing their time spent actively swimming. UGT8-IN-1 concentration Increasing the temperature from 17 °C to 23 °C doubled the energy utilized by post-larvae while swimming, while also reducing the time they spent swimming by three times. Therefore, increasing ocean temperatures appear to greatly affect the energetic cost and efficiency of shoreward migration of post-larvae in this lobster species, with the potential to markedly impact post-larval recruitment into coastal populations under future scenarios of ocean warming. Calcium oxide (CaO) is being considered as a possible treatment for both the control of echinoderm populations and the treatment against sea lice infestation in Norwegian salmon farms. CaO particles produce an exothermal reaction when in contact with water, which can cause epidermal burns and lesions to certain target organisms leading to death. The aim of the present study was to determine the effects of fine ( less then 0.8 mm) and coarse ( less then 2.5 mm) CaO particles to a range of marine species from different taxonomic groups two echinoderms (Asterias ruben and Strongylocentrotus droebachiensis); two crustaceans (Carcinus maenas and Tisbe battagliai); two molluscs (Mytilus edulis and Hinia reticulata); a polychaete (Nereis pelagica); a fish (Cyclopterus sp.); and seaweed germlings (Fucus vesiculosus). Overall, the fine CaO particles were more toxic to the selected marine species than the coarse particles. Coarse CaO particle effects were only observed in four of the nine species tested (A. rubens, S. droebachiensis, N. pelagica, T. battagliai) with similar LC50 values between 207 and 268 g/m2. For the fine CaO particles, the lowest LC50 was for the epibenthic copepod (T. battagliai) at 3.14 g/m2, followed by the sea urchin (20.1 g/m2), starfish (22.2 g/m2), ragworm (29.6 g/m2), and netted dog whelk (41.9 g/m2). Lump sucker fish exhibited significant mortalities only at the highest fine CaO concentration tested (320 g/m2) and recorded an LC50 of 226 g/m2. The toxicity data were used to generate species sensitivity distributions (SSDs) for both fine and coarse CaO particles. The hazard concentrations for 5% of the species (HC5) calculated from the SSDs, based on NOEC values, for the coarse and fine particles were 35.5 and 1.5 g/m2 respectively. Using a recommended assessment factor of 5, the Predicted No Effect Concentration (PNEC) was calculated as 7.1 and 0.3 g/m2 for coarse and fine CaO particles respectively. Shallow shipwrecks, can have severe ecological and toxicological impacts on coral atolls. In 2012, a tuna longliner ran aground on the reef crest of St Brandon’s Atoll, Mauritius, broke up into three pieces which was moved by currents and storms into the lagoon. In the months following the grounding, the coral around the wreck became dead and black. Down-current from the wreck, a dense bloom of filamentous algae (Ulva sp.) attached to coral occurred. To determine the ecological effects of the wreck on the system, the marine biota around the wreck, in the algal bloom, and fish reference zones were counted in 2014. Metal concentrations in reference and affected coral was determined using inductively coupled plasma mass spectrometry (ICP/MS). A pronounced difference was seen in the metal concentration pattern between coral from the wreck- and algal zones, and the coral reference zone. While the wreck zone contained the highest abundance of fish, the fish reference zone had the highest species diversity but with fewer fish. We also counted eleven Critically Endangered hawksbill sea turtles Eretmochelys imbricata and significantly more sea cucumbers in the algal zone than the reference zones. The effects of shipwrecks on coral reefs must be considered a threat over periods of years and should be studied further. With oil spills, and other sources of aromatic hydrocarbons, being a continuous threat to coral reef systems, and most reef fish species being protected or difficult to collect, the use of the invasive lionfish (Pterois volitans) might be a good model species to monitor biomarkers in potentially exposed fish in the Caribbean and western Atlantic. The rapid expansion of lionfish in the Caribbean and western Atlantic, and the unregulated fishing for this species, would make the lionfish a suitable candidate as biomonitoring species for oil pollution effects. However, to date little has been published about the responses of lionfish to environmental pollutants. For this study lionfish were collected in the Florida Keys a few weeks after Hurricane Irma, which sank numerous boats resulting in leaks of oil and fuel, and during the winter and early spring after that. Several biomarkers indicative of exposure to PAHs (bile fluorescence, cytochrome P450-1A induction, glutathione S-transferase activity) were measured. To establish if these biomarkers are inducible in PAH exposed lionfish, dosing experiments with different concentrations of High Energy Water Accommodated Fraction of crude oil were performed. The results revealed no significant effects in the biomarkers in the field collected fish, while the exposure experiments demonstrated that lionfish did show strong effects in the measured biomarkers, even at the lowest concentration tested (0.3% HEWAF, or 25 μg/l ƩPAH50). Based on its widespread distribution, relative ease of collection, and significant biomarker responses in the controlled dosing experiment, it is concluded that lionfish has good potential to be used as a standardized biomonitoring species for oil pollution in its neotropical realm. This study assesses the sex-specific effects induced by CdTe QDs, on the marine mussel Mytilus galloprovincialis in comparison to its dissolved counterpart. A 14 days exposure to CdTe QDs and dissolved Cd was conducted (10 μg Cd L-1), analysing Cd accumulation, oxidative stress, biotransformation, metallothionein and oxidative damage in the gonads. Both Cd forms caused significant antioxidant alterations, whereby QDs were more pro-oxidant, leading to oxidative damage, being females more affected. Overall, biochemical impairments on gonads of M. galloprovincialis demonstrate that the reproductive toxicity induced by CdTe QDs in mussels are sex-dependent and mediated by oxidative stress and lipid peroxidation. It is crucial to acknowledge how gametes are affected by metal-based nanoparticles, such as Cd-based QDs. As well as understanding the potential changes they may undergo at the cellular level during gametogenesis, embryogenesis and larval development potentially leading to serious impacts on population sustainability and ecosystem health.
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