NextGen - Potential for multiGENerational acclimation of fishes to ocean warming and acidification

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Publications

Long-snouted seahorse, Hippocampus guttulatus, under global warming

Publication . Costa, Ana B.; Correia, Miguel; Silva, Goncalo; Faria, Ana M.

The earth’s climate system and the global ocean have been warming up, since the mid-twentieth century and it is expected that the global and ocean´s temperature will rise in the next years even more [1,2,13,25,28]. For ectotherms, such as fish, temperature is a determinant cue for several behavioural [29], physiological [24], and metabolic processes [6]. Seahorses’ particular life history makes them vulnerable to human or natural disturbances [17]. The long snout seahorse, Hippocampus guttulatus, is one of the two species that inhabit the coastal areas of Portugal [23]. The present study aims to assess the effects of ocean warming on growth, feed intake and behavior patterns of adult H. guttulatus. Results provide clear evidence of detrimental effects of exposure to warming on this species. Under extreme temperatures (24ºC), the increased food ingestion was not enough for fish to support growth (weighted less), which suggests that fish were spending energy to counterbalance the thermal stress they were exposed to. Fish under both elevated temperature treatments (20 and 24ºC) were also spending more energy in active behaviours. Altogether, these data may indicate that ocean warming will have a drastic effect on seahorse populations currently inhabiting the Sado estuary.

2022Journal article

Open access

Elevated temperature, but not decreased pH, impairs reproduction in a temperate fish.

Publication . Lopes, Ana F.; Faria, Ana M.; Dupont, Sam

Fish reproductive success is linked to the ability of couples to mate and produce clutches that successfully hatch. Environmental stressors like high temperature and low pH can jeopardize this energetically costly process. In this study, exposure to high temperature and low pH was tested on a marine temperate species, Gobiusculus flavescens, to evaluate effects on reproductive performance. Breeding pairs were assigned to different temperatures (+ 0 °C, + 3 °C relative to in situ temperature) and pH levels (8.0, 7.6), in a cross-factorial design for a 3-month period. Reproduction activity, success, and paternal investment were measured throughout the exposure period. Results show reproduction is impaired by elevated temperature, while low pH had little impact. Breeding pairs under high temperature had 3% to 10% hatching success, up to 30% less eggs and eggs up to 20% smaller. Although paternal investment was not affected by tested parameters, males of breeding pairs exposed to elevated temperature had smaller gonadosomatic indexes, which might indicate a lack of investment in the reproductive process. Overall, results show that elevated temperature, expected more frequently in the near future, as a consequence of global warming, may impair key processes like reproduction in temperate fish, with potential consequences for fitness and population replenishment.

2020Journal article

Open access