Resilience of cold water aquaculture: a review of likely scenarios as climate changes in the Gulf of Maine

Abstract

Climate change is one of the biggest challenges facing development and continuation of sustainable aquaculture in temperate regions. We primarily consider the ecological and physical resilience of aquaculture in the Gulf of Maine (GoM), where a thriving industry includes marine algae, extensive and intensive shellfish aquaculture, and a well-established Atlantic salmon industry, as well as the infrastructure required to support these economically important ventures. The historical record of sea surface temperature in the GoM, estimated from gridded, interpolated in situ measurements, shows considerable interannual and decade-scale variability superimposed on an overall warming trend. Climate model projections of sea surface temperature indicate that the surface waters in the GoM could warm 0.5-3.5°C beyond recent values by the year 2100. This suggests that, while variability will continue, anomalous warmth of marine heatwaves that have been observed in the past decade could become the norm in the GoM ca. 2050, but with the most significant impacts to existing aquaculture along the southernmost region of the coast. We consider adaptations leading to aquacultural resilience despite the effects of warming, larger numbers of harmful nonindigenous species (including pathogens and parasites), acidification, sea-level rise, and more frequent storms and storm surges. Some new species will be needed, but immediate attention to adapt existing species (e.g. preserve/define wild biodiversity, breed for temperature tolerance and incorporate greater husbandry) and aquaculture infrastructure can be successful. We predict that these measures and continued collaboration between industry, stakeholders, government and researchers will lead to sustaining a vibrant working waterfront in the GoM.

Priming of Marine Macrophytes for Enhanced Restoration Success and Food Security in Future Oceans

“…First, priming the gametophyte generation of the kelp Alaria esculenta for 3 days at 22 • C (compared with 12 • C) enhanced their survival under increased temperatures, and the growth of the derived sporophyte generation (Quigley et al, 2018). Second, cultivation of Saccharina japonica gametophytes at 22-24 • C increased the heat-tolerance of the derived sporophytes by 2 • C (Wu and Pang, 1998) in Bricknell et al (2021). Third, in the fucoid brown alga Fucus vesiculosus, storage of parental tissue at a higher temperature (14 • C versus 4 • C), or acclimation of embryos to 29 • C significantly increased their survival by 30-50% under 33 • C (Li and Brawley, 2004).…”

Summer Is Coming! Tackling Ocean Warming in Atlantic Salmon Cage Farming

“…Overall warming trends have been more pronounced in the Northern than the Southern Hemisphere [ 24 ] and warming rates are generally greater at higher latitudes when compared to equatorial regions. In particular, MHW, defined as temperature anomalies where sea surface temperatures exceed the 90th percentile of the local long-term climatology for at least 5 consecutive days [ 25 ], can be particularly damaging for marine species [ 26 ], with potential impacts on aquaculture production (e.g., [ 27 ]). A study by Oliver et al [ 12 ] reported that MHW intensity and annual MHW days are increasing worldwide, with significant, widespread and persistent effects on marine ecosystems.…”

“…For example, the annual cumulative intensity of MHW has increased 340% over the past 30 years in southern Norway (Flødevigen Research Station) [ 30 ], with unusually high water temperatures (>18 °C) being registered in the south of Norway in recent years [ 31 ]. In the Gulf of Maine, where the salmon aquaculture industry is also well established, surface waters have increased at a rate of +0.23 °C per year in the past decade [ 27 ]. Moreover, records of a persistent MHW over the Gulf of Maine in 2012 led to a peak of >18 °C in sea surface temperature [ 27 ].…”

“…In the Gulf of Maine, where the salmon aquaculture industry is also well established, surface waters have increased at a rate of +0.23 °C per year in the past decade [ 27 ]. Moreover, records of a persistent MHW over the Gulf of Maine in 2012 led to a peak of >18 °C in sea surface temperature [ 27 ]. Another MHW was registered in the area in 2016.…”

Simulation of sugar kelp (Saccharina latissima) breeding guided by practices to prioritize accelerated research gains

“…They have also been an important source of human food. Due to climate change and other anthropogenic factors, global kelp populations have faced a drastic decline (Moy and Christie 2012, Wernberg et al 2019, Bricknell et al 2020. Now kelp farming is largely replacing wild harvests: over 30 million metric tons of seaweed were harvested in 2018, of which 97% came from farms (FAO, 2020).…”