Browsing by Author "Peck, Myron A."
Now showing 1 - 3 of 3
Results Per Page
Sort Options
- Foraging behaviour, swimming performance and malformations of early stages of commercially important fishes under ocean acidification and warmingPublication . Pimentel, Marta; Faleiro, Filipa; Marques, Tiago A.; Bispo, Regina; Dionísio, Gisela João Ribeiro Lemos; Faria, Ana Margarida; Machado, Jorge; Peck, Myron A.; Pörtner, Hans; Ferreira, Pedro Marques Pousão; Gonçalves, Emanuel João; Rosa, RuiEarly life stages of many marine organisms are being challenged by climate change, but little is known about their capacity to tolerate future ocean conditions. Here we investigated a comprehensive set of biological responses of larvae of two commercially important teleost fishes, Sparus aurata (gilthead seabream) and Argyrosomus regius (meagre), after exposure to future predictions of ocean warming (+4 °C) and acidification (ΔpH= 0.5). The combined effect of warming and hypercapnia elicited a decrease in the hatching success (by 26.4 and 14.3 % for S. aurata and A. regius, respectively) and larval survival (by half) in both species. The length for newly-hatched larvae was not significantly affected, but a significant effect of hypercapnia was found on larval growth. However, while S. aurata growth was reduced (24.8–36.4 % lower), A. regius growth slightly increased (3.2–12.9 % higher) under such condition. Under acidification, larvae of both species spent less time swimming, and displayed reduced attack and capture rates of prey. The impact of warming on these behavioural traits was opposite but less evident. While not studied in A. regius, the incidence of body malformations in S. aurata larvae increased significantly (more than tripled) under warmer and hypercapnic conditions. These morphological impairments and behavioural changes are expected to affect larval performance and recruitment success, and further influence the abundance of fish stocks and the population structure of these commercially important fish species. However, given the pace of ocean climate change, it is important not to forget that species may have the opportunity to acclimate and adapt.
- Ontogeny of swimming capacity in plaice (Pleuronectes platessa) larvaePublication . Silva, Luis; Moyano, Marta; Illing, Björn; Faria, Ana Margarida; Garrido, Susana; Peck, Myron A.Little is known regarding the swimming ability of the larvae of European plaice (Pleuronectes platessa) in relation to changes in total length (TL), dry weight (DW) and developmental stage, which is surprising given the importance of transport processes to the recruitment dynamics of this species in the North Sea and elsewhere. We investigated ontogenetic changes in the critical swimming speed (Ucrit) of plaice from hatching to the onset of metamorphosis (50 days post-hatch, dph) at 8 °C. The mean (±SD) TL and DW growth rates were 1.59 ± 0.81 and 7.7 ± 0.35 % d−1, respectively. Larvae were unable to swim at against a minimum current speed of <0.5 cm s−1 until 10 dph (7 mm TL), after which Ucrit significantly increased with increasing TL until the onset of metamorphosis and subsequent settlement. Mean (±SD) Ucrit was 0.38(0.35), 1.59(0.54), 2.27(0.49) and 2.99(0.37) cm s−1 for stage I (6.61 ± 2.64 mm TL), stage II (7.75 ± 0.60 mm TL), stage III (9.10 ± 1.00 mm TL) and stage IV (11.59 ± 0.85 mm TL) larvae, respectively. Larval TL, DW, DNA content, RNA content and Ucrit significantly increased, whereas sRD significantly declined as larvae developed from stage I to V. Although inter-individual differences in Ucrit (coefficient of variation, CV = 33 %) were as large as those in biochemical and morphological condition (CV’s of 21–42 %), differences in Ucrit were not significantly related to those in nutritional condition and larvae with lower DNA/DW had also better swimming abilities. These estimates should be useful to ongoing efforts to create individual- based models of the transport, foraging and growth of plaice larvae in the North Sea.
- Seasonal approach to forecast the suitability of spawning habitats of a temperate small pelagic fish under a high-emission climate change scenarioPublication . Lima, André R.A.; Garrido, Susana; Riveiro, I.; Rodrigues, Diana; Angélico, Maria M. P.; Gonçalves, Emanuel J.; Peck, Myron A.; Silva, GonçaloABSTRACT: Spawning habitats of cold-water, European small pelagic fishes have shifted poleward in the last three decades coincident with gradual ocean warming. We predicted present-day, season-specific habitat suitability for spawning by European sardine Sardina pichardus in the Atlantic Ocean and Mediterranean and Black Seas, and projected climate-driven changes in suitable areas from 2050-2099 under the IPCC – RCP 8.5 scenario. Sea surface temperature and distance to the coast had the greater influences in spawning habitats, reflecting the temperature- and coastal-dependent spawning of sardines. Chlorophyll-a was the third most important explanatory variable for spawning in winter to summer. Winds were predominantly important during autumn, whilst sea surface salinity was an important driver during spring and summer. Presentday, “hotspots” for spawning were identified in regions of highly productive, salty waters, where SST was between 6 and 18°C from autumn to spring or 16 and 25°C during summer and favourable winds occurred that would retain eggs and larvae closer to the coast (< 250 km). For future scenarios, forecasts indicate that environmental optima for spawning is projected to be in regions where SST varies between 11°C and 18°C from autumn to spring; and between 18°C and 24°C during summer. However, a negative relationship between phytoplankton productivity and habitat suitability induced by warming is likely to occur in the future. Projections suggest that suitable spawning habitats in all seasons will shift to higher latitudes, with a prominent range expansion along the coast of Norway during winter and autumn (> 83%). The total spawning area, however, was projected to contract in the future during spring (-10.5%) and autumn (-4.1%) due to losses of currently suitable areas along the Atlantic African Coast and Mediterranean Sea. Such regions currently support the greatest sardine stocks but climate-driven warming and decreased plankton productivity are projected to make these areas unsuitable for spawning and likely also for sardine fisheries in future.