Evaluating the promise and pitfalls of a potential climate change–tolerant sea urchin fishery in southern California

Abstract

Marine fishery stakeholders are beginning to consider and implement adaptation strategies in the face of growing consumer demand and potential deleterious climate change impacts such as ocean warming, ocean acidification, and deoxygenation. This study investigates the potential for development of a novel climate change-tolerant sea urchin fishery in southern California based on Strongylocentrotus fragilis (pink sea urchin), a deep-sea species whose peak density was found to coincide with a current trap-based spot prawn fishery (Pandalus platyceros) in the 200–300-m depth range. Here we outline potential criteria for a climate change-tolerant fishery by examining the distribution, life-history attributes, and marketable qualities of S. fragilis in southern California. We provide evidence of seasonality of gonad production and demonstrate that peak gonad production occurs in the winter season. S. fragilis likely spawns in the spring season as evidenced by consistent minimum gonad indices in the spring/summer seasons across 4 years of sampling (2012–2016). The resiliency of S. fragilis to predicted future increases in acidity and decreases in oxygen was supported by high species abundance, albeit reduced relative growth rate estimates at water depths (485–510 m) subject to low oxygen (11.7–16.9 µmol kg−1) and pHTotal (<7.44), which may provide assurances to stakeholders and managers regarding the suitability of this species for commercial exploitation. Some food quality properties of the S. fragilis roe (e.g. colour, texture) were comparable with those of the commercially exploited shallow-water red sea urchin (Mesocentrotus franciscanus), while other qualities (e.g. 80% reduced gonad size by weight) limit the potential future marketability of S. fragilis. This case study highlights the potential future challenges and drawbacks of climate-tolerant fishery development in an attempt to inform future urchin fishery stakeholders.

Changes in the biochemical and nutrient composition of seafood due to ocean acidification and warming

“…However, this in practicality might face new challenges, such as selecting species that also thrive under aquaculture conditions and avoiding selecting non-native species (Arismendi et al, 2009), and might require strategic management plants. In order to optimise protein supply and secure socio-economic benefits of mollusc aquaculture, research needs to focus on identifying and selecting native aquaculture species that are resilient to future climate conditions, and able to retain their beneficial nutritional properties (Cooley et al, 2012;Sato et al, 2018), without introducing new challenges.…”

Assessing relative post-release mortality for the transparent goby fishery: Environmental drivers and the utility of vitality metrics

“…In these cases, the survival of released fish remains unknown, underestimating the total mortality caused by fishing. This underestimation may affect the proper management of the fishery, which is based on the periodic review of daily catches and fishing effort [24]. The immediate mortality estimated in this study under average environmental conditions was low (average survival percentage of 99.9%, CI: 97.9-100%), but the asymptotic delayed mortality was considerably high (average survival percentage of 47.2%) and highly variable (CI between 33.8% and 65.8%).…”

“…In addition, a co-management committee was created with the participation of the public administration, fishers' associations, researchers, and nongovernmental organizations. This committee periodically revises the daily catches and the fishing effort and, if required (for example, if the monthly threshold is not reached), implements more restrictive measures (i.e., closing days) for sustaining the sale price and resources [24].…”

“…The survival of released fish may be affected by several biological processes, such as barotrauma, temperature shock, desiccation/air exposure/anoxia, light-related damage to the eyes, trauma related to handling or alteration of antipredator behavior [6,9,19]. In the case of the target species in the transparent goby fishery, desiccation/air exposure/anoxia seems to be irrelevant because fish from the codend are immediately released into a barrel with sea water for sorting or are collected using a hand net with the net still in the water (the target species tend to remain near the surface, which facilitates sorting) [24]. Furthermore, in the case of slipping, fish are directly released to the sea; thus, mortality related to desiccation/air exposure/ anoxia or even to onboard handling should be considered negligible.…”

Gene Expression Patterns of Red Sea Urchins (Mesocentrotus Franciscanus) Exposed to Different Combinations of Temperature and pCO2 During Early Development

“…Given the considerable ecological and economic importance of M. franciscanus, determining how this species will be affected by continuing environmental change in coastal oceans remains an overlooked and critical area of research [11]. Due to their habitat and life history, these urchins are threatened by climate change impacts [12] such as ocean warming, which may include sudden and extreme marine heat waves [13,14], and ocean acidi cation, which may amplify the low pH conditions that episodically occur in upwelling regions [15]. Furthermore, these urchins may be particularly vulnerable to stress during early development.…”