World Fisheries PDF

Over-exploitation of marine fishes has led to population collapses and raised concerns about their recovery and extinction risk. Empirical evidence shows that marine fishes exhibit very slow recovery after prolonged declines, contradicting the perception of high resilience. Analysis of 90 stocks r...

Over-exploitation of marine fishes has led to population collapses and raised concerns about their recovery and extinction risk. Empirical evidence shows that marine fishes exhibit very slow recovery after prolonged declines, contradicting the perception of high resilience. Analysis of 90 stocks reveals that many species, especially gadids (e.g., cod, haddock) and flatfishes, show little to no recovery even 15 years after significant reductions in reproductive biomass. - Herring and related species, which mature early and are fished selectively, might be exceptions to this slow recovery trend. Global overfishing has significantly increased the extinction probability of many targeted and incidentally harvested marine fishes. Agencies like IUCN and COSEWIC have listed several marine species as vulnerable or endangered based on significant population declines. Recovery rates among different fish families vary, with clupeids (e.g., herring) showing more resilience compared to other families like gadids and flatfishes. Clupeids\' higher recovery rates may be due to their earlier maturity, higher reproductive rates, and more selective fishing methods. Many marine fish stocks fail to recover rapidly due to management strategies aiming to maintain populations at 50% of their virgin biomass, which may not be suitable given the extensive exploitation history. Need for precautionary approaches in fisheries management to ensure the conservation of marine biodiversity. Define: Harvest by humans of wild aquatic organisms living in their natural environments - We catch and hunt, not harvest - The interaction of wild fish with fishing gear - Deployed by fishers - Location - Time - Results in catch - Fisheries science: Science of understanding the fish-gear-fisher-space-time-catch relationship and interactions - Aquaculture is not fisheries, it's a farming practice - 165 000 y ago: First evidence of seafood collection, South Africa - 125 000 y ago: First evidence of overfishing, Eritrea, Red Sea - Giant clam - Out of Africa: Resource depletion was a major driver for migration and geographic expansion of humanity - Intersection of human invasion impacts with gradual changes in climate drove the timing and geography of extinction in the Northern Hemisphere (NH) - 11 000 - 12 000 y ago: Invention of agriculture - Arose independently in various locations - Greater population density demanded more food than could be collected from the wild - Overhunting helped push megafauna to extinction - Changes in climate made it too cold/dry to rely on wild food sources alone - Hunting replaced by domesticated animal husbandry - Gathering replaces by farming - Fish remain undomesticated - International body: Food and Agriculture Organisation of United Nations (FAO) - Leads international efforts to defeat hunger and improve nutrition and food security - Global mandate on fisheries   - Committee on Fisheries and Aquaculture (COFI) - Global parliament of fisheries, meets every two years - Country reps - Drives/influences international policies on fisheries - Document supporting and informing COFI: SOFIA   - State of World Fisheries and Aquaculture (SOFIA) - Bi-annual - Present global data on fisheries - Presents a global assessment of the status of fisheries resources - Specialised topics   - Continuously rising trend in inland fisheries production may be misleading due to a data problem - Improved reporting over time at the country level, not the actual catches - Trends in production: - Finfish - inland (fresh water) aquaculture - Aquatic algae (mostly seaweed)   **FAO Mandate** - Mandate: UN General Assembly dependent and country sponsor dependent - Not politically or scientifically independent, instead driven by politics - Doesn\'t collect data - Report on data provided to FAO by countries - Non-reporting issues - Quality of data - Time series comprehensiveness back to 1950 - Only accept and use data on landed catches, not bycatch   - Several aspects are problematic: - \'Assessed stocks\' - Methods and approaches not fully transparent and not peer-reviewed - Time series bias by ignoring pre-1974 period   **SSP 2008** - 58% of stocks are overfished - 33% fully exploited - 10% undeveloped   **SSP vs FAO-SOFIA** - FAO used 445 \'assessed\' stocks accounting for 80% of global FAO catch data - SSP used 100% of global FAO catch data - Assessed stocks: - Dominated by \'good\' or \'successful\' fisheries (often managed) - FAOs decision criteria contain an inadvertent data selection bias   - Trends over time matter more than percentages - Data comprehensiveness matters - Be aware of, acknowledge and account for bias in your data selection