HUBBS-SEA WORLD RESEARCH INSTITUTE

SUSTAINABLE SEAFOOD Conducted scientific research on 25 sustainable seafood projects, feeding a hungry world and restoring depleted fish populations. Aquaculture is a practical solution to renewing regionally and economically important marine fisheries, producing domestic supplies of sustainable seafood and reducing the need for fresh water to produce terrestrial animal protein as a food source.During the previous fiscal year, we made significant progress in our white seabass fin clip feasibility program under the Ocean Resources Enhancement and Hatchery Program (OREHP), with support from NOAAs Saltonstall-Kennedy program. Volunteer anglers and citizen scientists actively participated in collecting fin clips from white seabass they caught, utilizing kits provided by HSWRI. In addition, muscle tissue and otoliths were extracted from white seabass heads donated by anglers and commercial processors, as part of the Save Your White Seabass Head Program. These samples were sent for analysis with fin clips and muscle tissue genotyped for genetic parentage assignment by the South Carolina Department of Natural Resources to differentiate hatchery-raised and wild fish. Otoliths were sectioned and analyzed for age and stable isotopes by HSWRI and partner institutions, further informing the interpretation of the genetic data. These efforts, contributed valuable insights into white seabass populations, supported sustainable fisheries management, and restorative aquaculture practices.We also completed a project aimed at understanding how water temperature during early development influenced sex determination in California halibut. Using eggs from our broodstock at our Mission Bay facility, we reared juvenile halibut under controlled thermal conditions ranging from 15C to 23C using a specially designed recirculating aquaculture system. Our research demonstrated that higher temperatures resulted in a higher proportion of males, with 98.2% male at 23C, 74.5% male at 19C, and a near 1:1 sex ratio at 15C. This study provided valuable insights for optimizing sex ratios and growth in hatcheries through thermal manipulation, contributing to our future stock enhancement and aquaculture efforts. Additionally, our findings may have broader implications for understanding the impact of global warming on wild population demographics.Our team worked on several projects this past year aimed at improving the feasibility of aquaculture as a commercial industry for food production. We tested a commercial-scale self-cleaning larval rearing tank designed to enhance the production of California yellowtail and white seabass. While the self-cleaning tank did not affect growth, it improved survival for white seabass and reduced labor by fourfold compared to control tanks. Additionally, we studied nutrient transfer from broodstock diets to eggs in California yellowtail, discovering that fatty acids from both commercial pellets and cut bait were incorporated into eggs within 10 to 19 days of feeding. This knowledge will help optimize broodstock diets for better egg quality. Finally, we evaluated the impact of different diets on egg quality in yellowtail broodstock, revealing the need for further research to develop nutritionally complete feeds that can support sustainable aquaculture practices. Together, these projects highlight our efforts to advance aquaculture as a viable source of healthy seafood protein to meet the needs of a growing world population. Over the past year, we made significant strides in advancing Integrated Multi-Trophic Aquaculture (IMTA) systems to enhance sustainability in the aquaculture industry. We developed a modular, land-based Integrated Multi-Trophic Recirculating Aquaculture System (IMTRAS) that combines culture systems for California yellowtail, sea cucumbers, mussels, and macroalgae (seaweed) to optimize resource use, reduce water consumption, and lower nutrient discharge. Initial trials demonstrated encouraging growth rates for both fish and macroalgae, with a local macroalgae serving as an efficient biofilter, significantly reducing nitrogen levels in the system. In a complementary study, we evaluated macroalgae's growth and nutrient removal in effluent from white seabass raceways, confirming nearly 100% ammonia removal and high algal productivity. Future efforts will focus on refining species density ratios to maximize nutrient recycling and expand seafood production. These projects highlight our ongoing commitment to developing sustainable and restorative aquaculture practices.

OCEAN HEALTH Conducted scientific research on 7 projects on ocean health, promoting a healthier planet where humans and marine life thrive together. To advance ocean health, we study ways to prevent disease transmission, promote ecosystem health and resilience, and provide rapid first response to marine life strandings and entanglements. HSWRI is responsible for stranding response and coordination for 222 km of the north and central east coast of Florida (~40% of Floridas east coast), as well as response within about 1800 km2 of estuarine waters. HSWRIs response area covers three coastal counties, including the federal lands within and surrounding the Kennedy Space Center, and HSWRI responds to more strandings than any other organization in Florida. This portion of Florida averages 67 strandings a year and is one of the most active areas for strandings in the southeastern U.S., receiving both live and dead cetaceans, including large whales, from mass strandings. HSWRI provided 24/7 first response to stranded whales and dolphins in Florida for over 50 events, including a rare beaked whale, striped dolphin, sperm whale, and killer whale, a species not observed stranded in the Southeast US in about 70 years. Response this year included 16 live-strandings, including Floridas second (and Brevard Countys first) grey seal stranding. Data collected by our team in Florida was included in a collaborative study examining the accumulation of trace elements, including essential nutrients and toxic heavy metals, in stranded toothed whales along the Florida and Georgia coasts. The entire dataset, gathered from tissue and fecal samples from 90 individuals across nine species, revealed that Risso's dolphins and short-finned pilot whales exhibited the highest concentrations of harmful metals such as mercury, cadmium, and lead. The study also found increasing levels of certain elements in pygmy and dwarf sperm whales over time, signaling growing environmental exposure. This collaborative effort underscores the importance of toothed whales as indicators of ocean health and environmental contamination, with far-reaching implications for human health.Our team in Florida published a comprehensive study examining the morbidity and mortality patterns of common bottlenose dolphins in the Indian River Lagoon from 2002 to 2020. The study analyzed 392 stranded dolphins, identifying causes of death in 57% of cases. The leading causes of death were inflammatory diseases, such as pneumonia, and trauma, mostly from human-related activities like entanglement and propeller strikes. Starvation peaked during the 2013 unusual mortality event, underscoring the vulnerability of this population. This research provides essential baseline data for the conservation and management of dolphins in the region.Over the past year, we have furthered the Institutes mission by establishing key partnerships with regional leaders in restorative aquaculture in Florida. Specifically, we have developed collaborations with organizations specializing in seagrass restoration and shellfish cultivation to enhance habitat recovery efforts. These partnerships allow us to tackle challenges associated with human disturbances, habitat degradation, pollution, and the impacts of climate change. By working across sectors, we can create more sustainable marine environments, supporting biodiversity and improving ecosystem resilience.