Marine Fisheries in Historical Perspective BIOL3305 PDF

JW Lewin, Fish Catch at Dawes Point, (1813). Art Gallery of South Australia BIOL3305 Marine fisheries in historical perspective Joseph Christensen, 1 October 2024 Overfishing: a 21st-century problem The damage done by overfishing goes beyond the marine envir...

JW Lewin, Fish Catch at Dawes Point, (1813). Art Gallery of South Australia BIOL3305 Marine fisheries in historical perspective Joseph Christensen, 1 October 2024 Overfishing: a 21st-century problem The damage done by overfishing goes beyond the marine environment. Billions of people rely on fish for protein, and fishing is the principal livelihood for millions of people around the world. Source: What is Overfishing? Facts, Effects and Overfishing Solutions (worldwildlife.org)  Does History matter in Fisheries Science? Today’s lecture: Shifting Baseline Syndrome & Fishing Down the Food Web Approaches to understanding past environmental change Benefits of a long-term perspective on oceans & seas Roman Fish Mosaic, Tarraco, 3rd Century CE Challenge of interdisciplinary research on marine fisheries Doing Marine Environmental History in the Indo-Pacific  History & Memory Images from Fremantle Sailing Club (Angling Division), early 2000s Shifting Baseline Syndrome Essentially, this syndrome has arisen because each generation of fisheries scientists accepts as a baseline the stock size and species composition that occurred at the beginning of their careers, and uses this to evaluate changes Daniel Pauly Shifting Baseline Syndrome When the next generation starts its career, the stocks have further declined, but it is the stocks at that time that serve as a new baseline. The result obviously is a gradual shift of the baseline… Daniel Pauly  Shifting Baseline Syndrome [Shifting Baseline Syndrome]... is a gradual shift of the baseline, a gradual accommodation of the creeping disappearance of resource species, and inappropriate reference points for evaluating economic losses resulting from overfishing, or for identifying targets for rehabilitation measures Pauly, D. (1995) Anecdotes and the Shifting Baseline Syndrome of Fisheries. Trends in Ecology & Evolution, 10, 430.  Taking stock: over-fishing since 1950 Spatial patterns of relative predator biomass in 1952 (a), 1958 (b), 1964 (c) and 1980 (d). Colour codes depict the number of fish caught per 100 hooks on pelagic longlines set by Japan’s fleet. Source: Myers, R., Worm, B. Rapid worldwide depletion of predatory fish communities. Nature 423, 280–283 (2003).  Innovative data & methodologies McClenachan, L. (2009), Documenting Loss of Large Trophy Trophy fish caught on Key Fish from the Florida Keys with Historical Photographs. West charter boats: (a) 1957, Conservation Biology, 23: 636-643 (b) early 1980s, and (c) 2007.  Fishing down marine food webs D. Pauly et al. (1998), Fishing down marine food webs. Science 279, p.860.  Drawing attention to global over-fishing “If we don't manage this resource, we will be left with a diet of jellyfish and plankton stew” (Daniel Pauly & Reg Watson, ‘Counting the last fish’, Scientific American, 1 July 2003). New York Times, 3 November 2006 Understanding human impacts on extended timescales Jeremy Jackson et al. (2001). Historical Overfishing and the Recent Collapse of Coastal Ecosystems. Science. 293(5530): 629-638  Understanding retrospective data: inter- disciplinary approaches Temporal (a) and spatial (b) availability of modern scientific (gray bars) and retrospective data. From: Heike K. Lotze, Boris Worm (2009), Historical baselines for large marine animals, Trends in Ecology & Evolution, Vol 24: 5, pp.254-262.  Reconstructing catches on centennial scales Reconstructed Annual Herring and Cod Catch in the North Atlantic, 1520–1790 From P. Holm et al. (2021), Accelerated extractions of North Atlantic cod and herring, 1520–1790. Fish and Fisheries (early view, 21 August).  Reconstructing long-term catch rates: examples from Australia Contribution per species to the total commercial CPUE, Botany Bay grounds, SE Aus Trawl Fishery, 1918-57. Neil Klaer, PhD thesis, 2006.  History of marine animal populations: key insights Historians have responded to the imperative of understanding the long-term impacts of human activity in the oceans and seas. Their analytical frameworks often embrace two basic premises: 1. Much of what we can know about the history of marine life will come from the ‘human edges’ of the ocean (i.e. coastal and near-shore ecosystems) 2. Historical analysis must combine with ecological analysis in innovative ways Fisheries history also sheds light on the role of marine resource in society and culture & Engraving of a Newfoundland fishery, 1738. drivers of change in human-ocean interaction From M. Kurlansky, Salt (2003). Adapted from: P. Holm et al. (2010) Marine Animal Populations: a New Look Back in Time, Life in the World’s Oceans  History of marine fisheries in the Indo-Pacific Our region (Indo-Pacific, or what historians call the ‘Indian Ocean World’) underlines the challenge of reconstructing histories of marine fisheries:  Biodiversity (what’s in a name?)  Cultural diversity (language)  High-value v. artisanal/subsistence fishing  Fishers in society (on the margins) Yet the implications are profound, in terms of livelihoods & food security Multi-disciplinarity is essential, with a particular role for anthropology/ ethnography:  The role of memory & oral tradition in augmenting fragmentary written records Fish market, Bali From: J. Christensen, ‘Unsettled seas: Towards a history of marine animal populations in the Central Indo-Pacific’ (2014) Historical insight and information in fisheries science In some fisheries, historical insight has been essential for establishing reference points for assessing stocks  What is a ‘virgin stock’ or ‘initial biomass’? Combining marine science methodologies with historical sources can:  Standardize CPUE across time  Provide biodiversity counts for the past  Comparing present environments to past ones; Bluefin Tuna, Tsukiji Fish Market, Japan  Identifying trends and fluctuations in diversity and abundance across time;  Hindcasting populations History also aids understanding of changing technologies & spatial patterns of fishing Enhancing arguments for marine conservation Left: 77lb Blue Groper, speared 2km off Whitford's Beach, WA, 1957. Right: 18kg Dhufish, caught just offshore at Marmion Marine Park, 1953.  Clarifying objectives and strategy in ecosystem restoration Swan River oyster beds, 1827 (left) and today (right). In: Christensen et al., ‘How a Dynamic Past Informs Shellfish Ecosystem Reconstruction at an Australian Urban Estuary’, Global Environment, 16:3, 2023.  Conclusion Concepts like Shifting Baseline Syndrome & Fishing Down the Food Web focus attention of longer-term (intergenerational) patterns of environmental change, and highlights the temporal limitations of catch statistics. Overcoming Shifting Baseline Syndrome requires innovative methodologies and therefore, inter-disciplinary perspectives and collaborations are essential Historical information and insight has various uses:  Past biodiversity counts & patterns of diversity and abundance  Understanding technological change & spatial expansion of fishing  Establishing reference points for stock assessments  Understanding the scale and extent of ecological change, and clarifying objectives and strategy in ecological restoration  History can also be a powerful trigger for conservation efforts Our (Indo-Pacific) region presents both opportunities and & challenges for reconstructing histories of marine fisheries