Ecopath 25 Years Conference Proceedings: Extended Abstracts, Pp
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Three Simple Rules for High Catches, High Profits and Healthy Ecosystems
Three simple rules for high catches, high profits and healthy ecosystems Position paper for the round-table discussion Towards a Sustainable Fishery Sector Block 2, Interactions between Fisheries and Nature, Wednesday 23 June 2021 by Rainer Froese, GEOMAR, Kiel, Germany, [email protected] Rule 1: Do not take out more than is regrown Taking out more than is regrown is called overfishing and will shrink the fished stock below levels that can produce the maximum longterm catch (MSY). Despite the legal obligation to end overfishing in 2020, the total allowed catches (TACs) for about 40% of the stocks with suitable data in the North Sea and adjacent waters constituted overfishing (1). Overfishing is stupid: with overfishing, more effort = money is spent to get lower catches than possible at lower value and with unnecessarily high impacts on the ecosystem. The lower value is caused by overfishing shrinking the mean size of the fish and smaller fish bring lower price per kg. Impact is unnecessary high because better catches can be obtained from non- overfished stocks with less gear deployment, therefore less by-catch and less physical impact. To end overfishing, catches have to be reduced for 1-4 years, depending on current stock size. The loss caused by such reduced catches is easily regained within a few years after rebuilt stock size allows for permanent high catches at e.g. 90% of the MSY level. The 90% MSY is needed for stability; with fishing at MSY, there is a 50% chance of shrinking the stock below the MSY level and thus reducing future catches. -
Red Sea Large Marine Ecosystem (Lme
III-6 Red Sea: LME #33 S. Heileman and N. Mistafa The Red Sea LME is bordered by Djibouti, Egypt, Eritrea, Israel, Jordan, Saudi Arabia, Sudan and Yemen. It has a surface area of 458,620 km2, of which 2.33% is protected and includes 3.8% of the world’s coral reefs (Sea Around Us 2007). It is characterised by dense, salty water formed by net evaporation with rates up to 1.4 - 2.0 m yr-1 (Hastenrath & Lamb 1979) and deep convection in the northern sector resulting in the formation of a deep water mass flowing out into the Gulf of Aden underneath a layer of less saline inflowing water (Morcos 1970). A dominant phenomenon affecting the oceanography and meteorology of the region is the Arabian monsoon. In winter, northeast monsoon winds extend well into the Gulf of Aden and the southern Red Sea, causing a seasonal reversal in the winds over this entire region (Patzert 1974). The seasonal monsoon reversal and the local coastal configuration combine in summer to force a radically different circulation pattern composed of a thin surface outflow, an intermediate inflowing layer of Gulf of Aden thermocline water and a vastly reduced (often extinguished) outflowing deep layer (Patzert 1974). Within the basin itself, the general surface circulation is cyclonic (Longhurst 1998). High evaporation and low precipitation maintain the Red Sea LME as one of the most saline water masses of the world oceans, with a mean surface salinity of 42.5 ppt and a mean temperature of 30° C during the summer (Sofianos et al. -
Structure and Dynamics of Demersal Assemblages on the Continental Shelf and Upper Slope Off Ghana, West Africa
MARINE ECOLOGY PROGRESS SERIES Vol. 220: 1–12, 2001 Published September 27 Mar Ecol Prog Ser Structure and dynamics of demersal assemblages on the continental shelf and upper slope off Ghana, West Africa Kwame A. Koranteng* Marine Fisheries Research Division, PO Box BT-62, Tema, Ghana ABSTRACT: Using two-way indicator species analysis and detrended correspondence analysis, species on the continental shelf and upper slope of Ghana were classified into 6 assemblages. The structure of the assemblages is determined primarily by depth and type of sediment on the seabed. There are clear faunal discontinuities around 30–40, 100 and 200 m depth. The dynamics of the assemblages are influenced by physico-chemical parameters of the water masses, mainly tempera- ture, salinity and dissolved oxygen, which are periodically modified by the seasonal coastal upwelling that occurs in the area. The observed changes in the composition and relative importance of species in the assemblages can be related to increased fishing activity and environmental forcing. KEY WORDS: Species assemblages · Structure and dynamics · Continental shelf and slope · Ghana Resale or republication not permitted without written consent of the publisher INTRODUCTION nental shelf using data from the Guinean Trawling Survey (Williams 1968). In fisheries, defining the aggregation of species in In the last 3 decades, significant changes have the ecosystem is the basis for managing species by the occurred in the biological and physical components of management unit approach (Tyler et al. 1982). Caddy the Gulf of Guinea marine ecosystem and in nearshore & Sharp (1986) also pointed out that such studies are forcing factors that could have an effect on species necessary to gain a better understanding of multi- aggregations in the sub-region (Koranteng 1998). -
Fisheries in Large Marine Ecosystems: Descriptions and Diagnoses
Fisheries in Large Marine Ecosystems: Descriptions and Diagnoses D. Pauly, J. Alder, S. Booth, W.W.L. Cheung, V. Christensen, C. Close, U.R. Sumaila, W. Swartz, A. Tavakolie, R. Watson, L. Wood and D. Zeller Abstract We present a rationale for the description and diagnosis of fisheries at the level of Large Marine Ecosystems (LMEs), which is relatively new, and encompasses a series of concepts and indicators different from those typically used to describe fisheries at the stock level. We then document how catch data, which are usually available on a smaller scale, are mapped by the Sea Around Us Project (see www.seaaroundus.org) on a worldwide grid of half-degree lat.-long. cells. The time series of catches thus obtained for over 180,000 half-degree cells can be regrouped on any larger scale, here that of LMEs. This yields catch time series by species (groups) and LME, which began in 1950 when the FAO started collecting global fisheries statistics, and ends in 2004 with the last update of these datasets. The catch data by species, multiplied by ex-vessel price data and then summed, yield the value of the fishery for each LME, here presented as time series by higher (i.e., commercial) groups. Also, these catch data can be used to evaluate the primary production required (PPR) to sustain fisheries catches. PPR, when related to observed primary production, provides another index for assessing the impact of the countries fishing in LMEs. The mean trophic level of species caught by fisheries (or ‘Marine Trophic Index’) is also used, in conjunction with a related indicator, the Fishing-in-Balance Index (FiB), to assess changes in the species composition of the fisheries in LMEs. -
Production and Maximum Sustainable Yield of Fisheries Activity in Hulu Sungai Utara Regency
E3S Web of Conferences 147, 02008 (2020) https://doi.org/10.1051/e3sconf/202014702008 3rd ISMFR Production and Maximum Sustainable Yield of fisheries activity in Hulu Sungai Utara Regency Aroef Hukmanan Rais* and Tuah Nanda Merlia Wulandari Balai Riset Perikanan Perairan Umum dan Penyuluhan Perikanan, Jln. Gub. HA Bastari, No.08 Jakabaring, Palembang, Indonesia Abstract. Production and fishing activities of inland waters in the Hulu Sungai Utara Regency (HSU) have a large contribution to fulfill the food needs for the local people in South Borneo. A total of 65% of the inland waters in the HSU Regency are floodplains. This research aimed to describe the production of capture fisheries products from 2010 to 2016, the catch per unit of effort (CPUE), the estimation of maximum sustainable (MSY), the biodiversity of fish species in the flood plain waters of Hulu Sungai Utara Regency (HSU). Research and field data collection was carried out throughout 2016, by collecting fishing gears and catch data from fishermen at Tampakang Village and Palbatu Village. The highest fish production was found in 2014, which reached a value of 2053 tons/year, and tended to decline in the following year. The highest catch per unit of effort per year was found to be in 2014 (151.65 tons/effort), and significantly dropped in 2016 (36.05 tons/effort). The Maximum Sustainable Yield (MSY) analysis obtained a value of 2103.13 tons/year with an effort value of 16.57 for standard fishing gear. The research identified 31 species of fish and the largest composition was baung (Mystusnemurus) and Nila (Tilapia nilotica). -
Resolving Geographic Expansion in the Marine Trophic Index
Vol. 512: 185–199, 2014 MARINE ECOLOGY PROGRESS SERIES Published October 9 doi: 10.3354/meps10949 Mar Ecol Prog Ser Contribution to the Theme Section ‘Trophodynamics in marine ecology’ FREEREE ACCESSCCESS Region-based MTI: resolving geographic expansion in the Marine Trophic Index K. Kleisner1,3,*, H. Mansour2,3, D. Pauly1 1Sea Around Us Project, Fisheries Centre, University of British Columbia, 2202 Main Mall, Vancouver, BC V6T 1Z4, Canada 2Earth and Ocean Sciences, University of British Columbia, 2207 Main Mall, Vancouver, BC V6T 1Z4, Canada 3Present address: NOAA, Northeast Fisheries Science Center, 166 Water St., Woods Hole, MA 02543, USA ABSTRACT: The Marine Trophic Index (MTI), which tracks the mean trophic level of fishery catches from an ecosystem, generally, but not always, tracks changes in mean trophic level of an ensemble of exploited species in response to fishing pressure. However, one of the disadvantages of this indicator is that declines in trophic level can be masked by geographic expansion and/or the development of offshore fisheries, where higher trophic levels of newly accessed resources can overwhelm fishing-down effects closer inshore. Here, we show that the MTI should not be used without accounting for changes in the spatial and bathymetric reach of the fishing fleet, and we develop a new index that accounts for the potential geographic expansion of fisheries, called the region-based MTI (RMTI). To calculate the RMTI, the potential catch that can be obtained given the observed trophic structure of the actual catch is used to assess the fisheries in an initial (usu- ally coastal) region. When the actual catch exceeds the potential catch, this is indicative of a new fishing region being exploited. -
The Yellow Sea Ecoregion: a Global Biodiversity Treasure
THE YELLOW SEA ECOREGION: Yellow Sea Ecoregion A GLOBAL BIODIVERSITY TREASURE A global biodiversity treasure under pressure A regional strategy and action plan A global treasure, a global responsibility The Yellow Sea LME is an important global resource. This The global importance of the Yellow Sea Ecoregion has been international waterbody supports substantial populations of recognised by governments and the international community in fish, invertebrates, marine mammals, and seabirds. Among the recent years. Starting in 1992, the Chinese and South Korean world's 64 large marine ecosystems (LMEs), the Yellow Sea governments together developed a transboundary approach to LME has been one of the most significantly affected by human the management of the Yellow Sea area with the assistance of development. Large human populations live in the basins that UNDP, UNEP, the World Bank, and NOAA. In 2005, a UNDP/GEF drain into the Yellow Sea. Seaside cities with tens of millions project, the Yellow Sea Large Marine Ecosystem project, was of inhabitants include Qingdao, Tianjin, Dalian, Shanghai, officially launched with participation of the Chinese and South Seoul/Inchon, and Pyongyang-Nampo. People in these urban Korean governments. areas are dependent on the Yellow Sea as a source of food, Meanwhile, in 2002, WWF and other conservation NGOs and economic development, recreation, and tourism. research institutes in China, South Korea and Japan began an Yet the Yellow Sea is under serious threat from industrial and assessment of Yellow Sea Ecoregion biodiversity. The objective agricultural waste, extensive economic development in the of this regional partnership was to prioritise conservation actions coastal zone, the unsustainable exploitation of natural resources, based on scientific data. -
Ecosystem Modelling in the Eastern Mediterranean Sea: the Cumulative Impact of Alien Species, Fishing and Climate Change on the Israeli Marine Ecosystem
Ecosystem modelling in the Eastern Mediterranean Sea: the cumulative impact of alien species, fishing and climate change on the Israeli marine ecosystem PhD Thesis 2019 Xavier Corrales Ribas Ecosystem modelling in the Eastern Mediterranean Sea: the cumulative impact of alien species, fishing and climate change on the Israeli marine ecosystem Modelización ecológica en el Mediterráneo oriental: el impacto acumulado de las especies invasoras, la pesca y el cambio climáti co en el ecosistema marino de Israel Memoria presentada por Xavier Corrales Ribas para optar al título de Doctor por la Universidad Politécnica de Cataluña (UPC) dentro del Programa de Doctorado de Ciencias del Mar Supervisores de tesis: Dr. Marta Coll Montón. Instituto de Ciencias del Mar (ICM-CSIC), Barcelona, España Dr. Gideon Gal. Centro de Investigación Oceanográfica y Limnológica de Israel (IOLR), Migdal, Israel Tutor: Dr. Manuel Espino Infantes. Universidad Politécnica de Cataluña (UPC), Barcelona, España Enero 2019 This PhD thesis has been framed within the project DESSIM ( A Decision Support system for the management of Israel’s Mediterranean Exclusive Economic Zone ) through a grant from the Israel Oceanographic and Limnological Research Institute (IORL). The PhD has been carried out at the Kinneret Limnological Laboratory (IOLR) (Migdal, Israel) and the Institute of Marine Science (ICM-CSIC) (Barcelona, Spain). The project team included Gideon Gal (Kinneret Limnological Laboratory, IORL, Israel) who was the project coordinator and co-director of this thesis, Marta Coll (ICM- CSIC, Spain), who was co-director of this thesis, Sheila Heymans (Scottish Association for Marine Science, UK), Jeroen Steenbeek (Ecopath International Initiative research association, Spain), Eyal Ofir (Kinneret Limnological Laboratory, IORL, Israel) and Menachem Goren and Daphna DiSegni (Tel Aviv University, Israel). -
Welcome to Fishbase
Welcome to FishBase FishBase contains different things for different people FishBase is an information system with key data on the biology of all fishes. Similar to an encyclopedia, FishBase contains different things for different people. For example, fisheries managers will dive into the largest existing compilation of population dynamics data; teachers and students will find numerous graphs illustrating basic concepts of fish biology; conservationists will use the lists of threatened fishes for any given country; policymakers may be interested in a chronological, annotated list of introductions to their country; research scientists, as well as funding agencies, will find it useful to gain a quick overview of what is known about a certain species; zoologists and physiologists will have the largest existing compilations of fish morphology, metabolism, gill area, brain size, eye pigment, or swimming speed at their fingertips; ecologists will likewise use data on diet composition, trophic levels, food consumption and predators as inputs for their models; the fishing industry will find proximate analyses, as well as processing recommendations for many marine species; anglers will enjoy a listing of all game fishes occurring in a particular country; and scholars interested in local knowledge will find more than 300,000 common names of fishes together with the language/culture in which they are used and comments on their etymology. Unexpected usage of FishBase The above text shows the usage of FishBase that we expected when we first published it on CD- ROM and later on the Internet, in the late 1990s. That assessment has been largely correct with regard to scientific use, which led to over 5000 citations of FishBase as counted by Google Scholar. -
Variability of Large Marine Ecosystems in Response to Global Climate Change
Sherman et al. ICESCM 2007/D:20 ICES CM 2007/D:20 Variability of Large Marine Ecosystems in response to global climate change K. Sherman, I. Belkin, J. O’Reilly and K. Hyde Kenneth Sherman, John O’Reilly, Kimberly Hyde USDOC/NOAA, NMFS Narragansett Laboratory 28 Tarzwell Drive Narragansett, Rhode Island 02882 USA +1 401-782-3210 phone +1 401 782-3201 FAX [email protected] [email protected] [email protected] Igor Belkin Graduate School of Oceanography University of Rhode Island 215 South Ferry Road Narragansett, Rhode Island 02882 USA +1 401 874-6728 phone +1 401 874-6728 FAX [email protected] Abstract: A fifty year time series of sea surface temperature (SST) and time series on fishery yields are examined for emergent patterns relative to climate change. More recent SeaWiFS derived chlorophyll and primary productivity data were also included in the examination. Of the 64 LMEs examined, 61 showed an emergent pattern of SST increases from 1957 to 2006, ranging from mean annual values of 0.08°C to 1.35°C. The rate of surface warming in LMEs from 1957 to 2006 is 4 to 8 times greater than the recent estimate of the Japan Meteorological Society’s COBE estimate for the world oceans. Effects of SST warming on fisheries, climate change, and trophic cascading are examined. Concern is expressed on the possible effects of surface layer warming in relation to thermocline formation and possible inhibition of vertical nutrient mixing within the water column in relation to bottom up effects of chlorophyll and primary productivity on global fisheries resources. -
Supplement A: Assumptions and Equations in Ecopath with Ecosim Governing Equations
Transactions of the American Fisheries Society 145:136–162, 2016 © American Fisheries Society 2016 DOI: 10.1080/00028487.2015.1069211 Supplement A: Assumptions and Equations in Ecopath with Ecosim Governing Equations The Ecopath module of EwE is a static, mass-balance ecosystem model that uses two governing equations for each species and age group (Christensen and Walters 2004). The first governing equation describes each species group’s production for a time period, i.e., production (P) is the sum of fishery catch (F), predation (M2), net migration (immigration, I, and emigration, E), biomass accumulation (BA), and mortality from other sources (‘other mortality’, M0): P = F + M2 + (I - E) + BA - M0 The second governing equation is based on the principle of conservation of matter within a group, and is designed to balance the energy flows of a biomass pool, i.e., consumption (C) equals the sum of production (P), respiration (R), and unassimilated food (U): C = P + R + U At a minimum, Ecopath requires inputs of diet composition (DCi,j, where i is predator and j is prey), fishery catch (Yi), and three of the following four parameters for each model group (i): biomass (Bi), production-to-biomass ratio (Pi/Bi), consumption-to-biomass ratio (Qi/Bi), and the ecotrophic efficiency (EEi, the fraction of the production that is used in the system and does not move directly to the detritus pool). Mass-balance principles are then used to estimate the fourth parameter. P/B is the annual production rate of the population in Ecopath. Under equilibrium conditions, the P/B ratio of fish is equivalent to its total annual instantaneous mortality (Z) (Allen 1971). -
Seafood Watch® Standard for Fisheries
1 Seafood Watch® Standard for Fisheries Table of Contents Table of Contents ............................................................................................................................... 1 Introduction ...................................................................................................................................... 2 Seafood Watch Guiding Principles ...................................................................................................... 3 Seafood Watch Criteria and Scoring Methodology for Fisheries ........................................................... 5 Criterion 1 – Impacts on the Species Under Assessment ...................................................................... 8 Factor 1.1 Abundance .................................................................................................................... 9 Factor 1.2 Fishing Mortality ......................................................................................................... 19 Criterion 2 – Impacts on Other Capture Species ................................................................................ 22 Factor 2.1 Abundance .................................................................................................................. 26 Factor 2.2 Fishing Mortality ......................................................................................................... 27 Factor 2.3 Modifying Factor: Discards and Bait Use .................................................................... 29 Criterion