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There is an urgent need to analyse and understand small-scale fisheries environment under biotic and abiotic stressors. In this work, we use a kelp forest ecosystem in Baja California, Mexico to present a novel approach, comparing two network models based on different information sources. First, we developed a conventional scientific knowledge network model (CSK) parameterized with in-situ observations. Second, we used a local ecological knowledge network model (LEK) based on interviews with local fishers. Our main objectives were: (a) verify if the two knowledge sources generated comparable models, and (b) explore model responses to disturbance scenarios. The CSK model presented greater detail at lower trophic levels, contrary to the LEK model. Additionally, we simulated top-down and bottom-up ecological disturbances. With a top-down disturbance, the groups' abundance increased following a cascade effect whereas, in the bottom-up disturbance, changes did not transfer uniformly. We also simulated anthropogenic disturbances through fishing pressure on three target species (lobsters, sea urchins, and sea bass). Our findings show similar patterns with the highest degree of change when lobsters are removed. Our findings highlight the potential of model complementarity and support the relevance of ecological network models to navigate future climate and anthropogenic uncertainty. [ABSTRACT FROM AUTHOR]

Extreme warming events have diminished kelp ecosystems around the world, but few reports exist about their impacts on invasive species. Warming events along the coast of Baja California from 2014 to 2016 negatively affected kelp forest communities historically dominated by Macrocystis pyrifera. We measured changes in the macroalgal community at Todos Santos Islands, Baja California, Mexico between 2018 and 2019. Our results documented a dramatic reduction of M. pyrifera, and a concurrent structural shift to invasive kelps dominance, with Sargassum horneri and Undaria pinnatifida being highly abundant in 2019. This study provides insights about impacts of invasive kelp species on macroalgal community structure under future climate scenarios. [ABSTRACT FROM AUTHOR]

In recent decades, global abalone aquaculture has significantly increased, while wild abalone fishery landings have decreased drastically, shifting production from fishing to farming. In California (USA) and Baja California (Mexico), overfishing and climate changelinked diseases are thought to be responsible for mass mortalities and significant declines in abalone fisheries landings. Conservation aquaculture is an option for enhancing abalone populations through captive propagation and cage mariculture with subsequent restockings into the wild. To test, inform, and promote innovative sustainable seafood production strategies in the Northeastern Pacific, we designed an experimental mariculture system at San Jeronimo Island, Baja California. We explored the feasibility of rearing juvenile red abalone, Haliotis rufescens, in a near-shore mariculture cage-based production system to supply individuals for local restoration programs. We tested the effects of 2 different depths, surface and bottom (5 m), and 3 macroalgal diets (Macrocystis pyrifera, Eisenia arborea, and a mixed diet of Pelagophycus porra with M. pyrifera) on the survival and growth of juvenile red abalone (32 ± 3.33 mm in shell length) inside cages attached to a long-line system. Over the 90-d experiment, survival was 99% for the surface treatment and 95% for the bottom treatment. Mean daily increment in shell length was 93 ± 12 µm·d-1 in surface cages and 82 ± 13 µm·d-1 in bottom cages. Depth did not affect growth or survival. Growth was highest using the E. arborea diet (99 ± 7 µm·d-1) but not significantly different from the M. pyrifera and mixed diets (88 ± 10 and 74 ± 13 µm·d-1, respectively). High survivorship and growth indicate that San Jeronimo Island can support cage-based mariculture of red abalone and that this strategy may be a useful tool in developing climate-resilient abalone restoration solutions aimed at bolstering seafood production. [ABSTRACT FROM AUTHOR]