UC San Diego

In the marine environment, political borders are essentially imaginary lines that often divide well-connected populations, communities and habitats. Scientific evidence shows that collaboration among nations can improve the effectiveness of program management, and cost efficiency. Despite the evidence that the marine region between California (U.S.) and Baja California (Mexico) constitutes a single ecoregion, our research revealed a lack of binational collaboration and differences in knowledge, and management of trans-boundary marine species. Chapter 1 asks what the fish composition of the Cedros archipelago is, and if the affinity of the species would allow us to recognize the biogeographic break between temperate and subtropical systems. We found that the Cedros archipelago fish community is a species-rich assemblage, with a fairly even blend of temperate and tropic-subtropical species. Nineteen new species occurrences were recorded in the archipelago, and limited sampling effort south of the U.S.-Mexico border may be the most likely reason. Chapter 2 asks whether the management of the giant sea bass (Stereolepis gigas) across political borders could result in loss of economic opportunities and threaten populations through overfishing. We found that extremely strong asymmetry management exists across the border, political regulations have both hidden and created illusions of false historical population collapses, and the total population size is likely higher than previously estimated. Chapter 3 seek to estimate the economic value of the giant kelp forest ecosystems across the Northeastern Pacific, based on some of the most important fisheries in the region. We found a positive relationship between kelp forest cover and the fisheries production, the higher the kelp cover, the higher the fishery production. Chapter 4 aims to analyze the effects of climate change in the giant kelp forest ecosystem across the U.S.-Mexico border and what the future scenario would be in the face of the current climatic trends. Our literature review showed that the giant kelp and the biological communities it supports will likely react to climatic and non-climatic changes in complex ways, likely by contracting their southern extent due to warming waters, reductions in nutrient availability, increasing wave disturbance, and grazing by warm-water herbivores. As a result, the best strategy in the long run is transboundary cooperation through sharing cross-border marine resources and acknowledging the actions taken by one of the invariable parties affects the other. Our results highlight the need for greater cross-border cooperation in marine resources management and generate research political-borderless.