Embryonic response to long‐term exposure of the marine crustacean Nephrops norvegicus to ocean acidification and elevated temperature

Abstract

Due to anthropogenic CO2 emissions, our oceans have gradually become warmer and more acidic. To better understand the consequences of this, there is a need for long-term (months) and multistressor experiments. Earlier research demonstrates that the effects of global climate change are specific to species and life stages. We exposed berried Norway lobsters (Nephrops norvegicus), during 4 months to the combination of six ecologically relevant temperatures (5–18°C) and reduced pH (by 0.4 units). Embryonic responses were investigated by quantifying proxies for development rate and fitness including: % yolk consumption, mean heart rate, rate of oxygen consumption, and oxidative stress. We found no interactions between temperature and pH, and reduced pH only affected the level of oxidative stress significantly, with a higher level of oxidative stress in the controls. Increased temperature and % yolk consumed had positive effects on all parameters except on oxidative stress, which did not change in response to temperature. There was a difference in development rate between the ranges of 5–10°C (Q10: 5.4) and 10–18°C (Q10: 2.9), implicating a thermal break point at 10°C or below. No thermal limit to a further increased development rate was found. The insensitivity of N. norvegicus embryos to low pH might be explained by adaptation to a pH-reduced external habitat and/or internal hypercapnia during incubation. Our results thus indicate that this species would benefit from global warming and be able to withstand the predicted decrease in ocean pH in the next century during their earliest life stages. However, future studies need to combine low pH and elevated temperature treatments with hypoxia as hypoxic events are frequently and increasingly occurring in the habitat of benthic species.

A review and meta‐analysis of the effects of multiple abiotic stressors on marine embryos and larvae

“…(and salinity, for arthropods only). Early life stages of lobsters are resilient to individual and combined effects of temperature and acidification (Styf et al ., ), and ocean acidification does not have a pronounced effect on the adult (Wittmann & Pörtner, ) or early life stages (Egilsdottir et al ., ; Pansch et al ., ; Arnberg et al ., ) of several arthropod species. This supports field observations at CO 2 vent sites where communities at gas release points are dominated by amphipods and noncalcifying polychaetes (Kroeker et al., ).…”

“…Overall, both molluscs and echinoderms seem equally vulnerable to ocean acidification at premetamorphic stages (Fig. 6) (Parker et al, 2010;Byrne et al, 2011), although intertidal and infaunal species may show increased resilience due to adaptation to pH fluctuations in rock pools (Davis et al, 2013) or low pH in sediments (Talmage & Gobler, 2011;Styf et al, 2013;Nguyen & Byrne, 2014). The impacts of acidification on calcification on echinoderms appear largely due to metabolic change (Byrne et al, 2013a;Evans et al, 2014) and less so to their vulnerable high magnesium calcite skeleton (Andersson et al, 2008).…”

Socio-economic Impacts—Fisheries

“…Several major programmes of research are underway in Europe to determine the possible consequences of future ocean acidification. In laboratory studies, significant effects have been noted for several important commercial shellfish species, notably mussels, oysters, lobster and Nephrops (Gazeau et al 2010;Agnalt et al 2013;Styf et al 2013).…”

Seasonal changes in the biochemical composition of females and offspring of red squat lobster, Pleuroncodes monodon (Decapoda, Munididae), from the Southeastern Pacific

“…For example, changes in environmental conditions affect the amount of energy that can be stored in the hepatopancreas (i.e. storage energy organ for reproduction: Nagaraju, ), duration of embryonic development (Fischer, Thatje, & Brey, ; Wehrtmann & López, ) and the metabolic rate of eggs (Alter, Paschke, Gebauer, Cumillaf, & Pörtner, ; Brante et al., ; Styf, Skold, & Eriksson, ), as well as the energy reserves (e.g. lipids) and structural components (e.g.…”