Warmer temperature decreases the maximum length of six species of marine fishes, crustacean, and squid in New Zealand

Abstract

As global oceans continue to warm and deoxygenate, it is expected that marine ectotherms will reduce in body size resulting from the interactive effects of temperature and dissolved oxygen availability. A temperature-size response describes how wild populations of ectothermic species grow faster and reach a smaller size within warmer temperatures. While temperature-size responses are well observed in marine ectotherms, the mechanisms underpinning such a reduction in body size remain debated. Here, we analyse the relative influence of temperature, dissolved oxygen concentration, and geographic location (which encompasses multiple latent variables), on the maximum body length of four fish, one crustacean, and one squid species, which inhabit shallow to deep sea (1000 m) New Zealand waters across a temperature gradient of 1.5 to 18 °C. We found that all study species displayed a temperature-size response, with the strongest response exhibited by the largest species, hoki (Macruronus novaezelandiae). We also found that temperature was more important than dissolved oxygen concentration in determining maximum body length, as dissolved oxygen levels were at or near saturation in the study area. Our results suggest that larger-bodied species may experience the strongest temperature-size responses, and support expectations from the gill-oxygen limitation theory (GOLT) and the oxygen and capacity limited thermal tolerance (OCLTT) concept that increases in oxygen demand may be size- and temperature-dependent, thus driving a reduction in maximum body length of marine ectotherms with warming.

Fishery catch is affected by geographic expansion, fishing down food webs and climate change in Aotearoa, New Zealand

“…Further shifts may alter community structure ( García Molinos et al, 2016 ; Poloczanska et al, 2016 ), food web interactions ( Tekwa, Watson & Pinsky, 2022 ), and fisheries catch ( Cheung et al, 2010 ; Cheung, Watson & Pauly, 2013 ). Ocean warming can also impact the fitness of marine ectotherms, particularly large, active predatory species ( Forster, Hirst & Atkinson, 2012 ; van Rijn et al, 2017 ; Lavin et al, 2022 ). Concurrently, historical fishing pressure has resulted in deleterious impacts on marine communities and ecosystems ( Howarth et al, 2014 ).…”

Length–Weight Relationships, Growth Models of Two Croakers (Pennahia macrocephalus and Atrobucca nibe) off Taiwan and Growth Performance Indices of Related Species

“…Establishing appropriate aging procedures and selecting representative growth models are thus important steps in developing stock assessments [1,6]. Even if the growth curve has been estimated previously, reviewing the change in key parameters by a timely repeat of estimation is also beneficial to monitoring the stock status under fishing pressure and climate change [7][8][9][10][11].…”

Temperature alters the predator-prey size relationships and size-selectivity of Southern Ocean fish

“…At the community level, larger ectotherms may decline in size more rapidly than smaller ectotherms with warming as a result of their reduced surface area to body mass ratio and the associated challenge of maintaining a higher metabolic rate 5,18 . This is particularly true for the marine environment, where larger fish and invertebrates display the strongest temperature-size responses 19 . If warming causes a greater decline in the size of ectotherm predators relative to that of their smaller prey (i.e.…”