From verge of collapse to ecosystem-based fisheries management Rainer Froese RD3 Seminar GEOMAR, Kiel, 15.05.2014

Overview Overview of fisheries-related research The reformed Common Fisheries Policy The MSY concept New approaches to estimate MSY Safe biological limits Size matters Questions

Overview of fisheries-related research

Fisheries-relevant Research in Recent Years See www. fishbase Fisheries-relevant Research in Recent Years See www.fishbase.de/rfroese for PDFs Martell, S. and R. Froese, 2013. A simple method for estimating MSY from catch and resilience. Fish and Fisheries 14: 504-514, doi:10.1111/j.1467-2979.2012.00485.x Froese, R. and M. Quaas. 2013. Rio+20 and the reform of the Common Fisheries Policy in Europe. Marine Policy 39:53-55, doi.org/10.1016/j.marpol.2012.10.007 Villasante, S., D. Gascuel and R. Froese. 2012. Rebuilding fish stocks and changing fisheries management, a major challenge for the Common Fisheries Policy reform in Europe. Ocean and Coastal Management 70:1-3, Froese, R. and M. Quaas. 2012. Mismanagement of the North Sea cod by the European Council. Ocean and Coastal Management 70:54-58, doi:10.1016/j.ocecoaman.2012.04.005 Quaas, M., R. Froese, H. Herwartz, T. Requate, J.O. Schmidt and R. Voss. 2012. Fishing industry borrows from natural capital at high shadow interest rates. Ecological Economics, doi:10.1016/j.ecolecon.2012.08.002 Froese, R. and A. Proelss. 2012. Is a stock overfished if it is depleted by overfishing? A response to the rebuttal of Agnew et al. to Froese and Proelss “Evaluation and legal assessment of certified seafood”. Marine Policy 38:548-550, doi:10.1016/j.marpol.2012.07.001 Froese, R. and A. Proelss. 2012. Evaluation and legal assessment of certified seafood. Marine Policy 36:1284-1289, doi:10.1016/j.marpol.2012.03.017 Froese, R., D. Zeller, K. Kleisner and D. Pauly. 2012. What catch data can tell us about the status of global fisheries. Marine Biology 159: 1283-1292, doi:10.1007/s00227-012-1909-6

More Kleisner, K., D. Zeller, R. Froese and D. Pauly. 2012. Using global catch data for inferences on the world's marine fisheries. Fish and Fisheries doi: 10.1111/j.1467-2979.2012.00469.x Norse, E.A., S. Brooke, W.W.L. Cheung, M.R. Clark, I. Ekeland, R. Froese, K.M. Gjerde, R.L. Haedrich, S.S. Heppell, T.Morato, L.E. Morgan, D. Pauly, R. Sumaila and R. Watson. 2012. Sustainability of deep-sea fisheries. Marine Policy 36:307-320, Pauly, D. and R. Froese. 2012. Comments on FAO's State of Fisheries and Aquaculture, or 'SOFIA 2010'. Marine Policy 36:746-752. Froese, R. and M. Quaas. 2011. Three options for rebuilding the cod stock in the eastern Baltic Sea. Marine Ecology Progress Series 434:197-2011 Froese, R. 2011. Fishery reform slips through the net. Nature 475:7 Froese, R., T.A. Branch, A. Proelß, M. Quaas, K. Sainsbury and C. Zimmermann. 2011. Generic harvest control rules for European fisheries. Fish and Fisheries 12:340-351 Khalilian, S., R. Froese, A. Proelss, T. Requate. 2010. Designed for Failure: A Critique of the Common Fisheries Policy of the European Union. Marine Policy 34:1178-1182 Froese, R. and A. Proelß. 2010. Rebuilding fish stocks no later than 2015: will Europe meet the deadline? Fish and Fisheries 11:194-202, Froese, R. 2008. The continuous smooth hockey stick: a newly proposed spawner-recruitment model. Journal of Applied Ichthyology 24: 703-704, Froese, R., A. Stern-Pirlot, H. Winker and D. Gascuel. 2008. Size Matters: How Single-Species Management Can Contribute To Ecosystem-based Fisheries Management. Fisheries Research 92:231-241 Froese, R. 2004. Keep it simple: three indicators to deal with overfishing. Fish and Fisheries 5:86-91

The Reformed Common Fisheries Policy

The new CFP Article 2.2 The CFP shall apply the precautionary approach to fisheries management, and shall aim to ensure that exploitation of living marine biological resources restores and maintains populations of harvested species above levels which can produce the maximum sustainable yield.

CFP and the Ecosystem Approach Preamble of CFP Whereas: ... (11) The CFP should contribute to the protection of the marine environment, to the sustainable management of all commercially exploited species, and in particular to the achievement of good environmental status by 2020, as set out in Article 1(1) of Directive 2008/56/EC of the European Parliament and of the Council1. (13) An ecosystem-based approach to fisheries management needs to be implemented, environmental impacts of fishing activities should be limited and unwanted catches should be avoided and reduced as far as possible.

CFP and the Ecosystem Approach Article 4.1 (9) 'ecosystem-based approach to fisheries management' means an integrated approach to managing fisheries within ecologically meaningful boundaries which seeks to manage the use of natural resources, taking account of fishing and other human activities, while preserving both the biological wealth and the biological processes necessary to safeguard the composition, structure and functioning of the habitats of the ecosystem affected, by taking into account the knowledge and uncertainties regarding biotic, abiotic and human components of ecosystems; Article 4.1 (11) 'low impact fishing' means utilising selective fishing techniques which have a low detrimental impact on marine ecosystems or which may result in low fuel emissions, or both;

CFP and Protected Areas Preamble of CFP (22) In order to contribute to the conservation of living aquatic resources and marine ecosystems, the Union should endeavour to protect areas that are biologically sensitive, by designating them as protected areas. In such areas, it should be possible to restrict or to prohibit fishing activities. When deciding which areas to designate, particular attention should be paid to those in which there is clear evidence of heavy concentrations of fish below minimum conservation reference size and of spawning grounds, and to areas which are deemed to be bio-geographically sensitive. Account should also be taken of existing conservation areas. [....]

Article 8, Establishment of fish stock recovery areas 1 Article 8, Establishment of fish stock recovery areas 1. The Union shall, while taking due account of existing conservation areas, endeavour to establish protected areas due to their biological sensitivity, including areas where there is clear evidence of heavy concentrations of fish below minimum conservation reference size and of spawning grounds. In such areas fishing activities may be restricted or prohibited in order to contribute to the conservation of living aquatic resources and marine ecosystems.

CFP and Minimizing Impact of Fishing Article 2.3 The CFP shall implement the ecosystem-based approach to fisheries management so as to ensure that negative impacts of fishing activities on the marine ecosystem are minimised, and shall endeavour to ensure that aquaculture and fisheries activities avoid the degradation of the marine environment.

Article 4.1 (17) 'minimum conservation reference size' means the size of a living marine aquatic species taking into account maturity, as established by Union law, below which restrictions or incentives apply that aim to avoid capture through fishing activity; such size replaces, where relevant, the minimum landing size;

The MSY concept

MSY, Bmsy and Fmsy MSY is the maximum sustainable yield Biomass (B) is the weight of the fish in the sea Bmsy is the biomass that can produce MSY Fmsy is the fishing pressure that eventually results in Bmsy and MSY A stock is and remains in good status if B > Bmsy and F < Fmsy

Background of the MSY Concept Schaefer 1954; BioDivPopGrowthMSY.xls

Surplus Production Implications Surplus production (Y) is the production of biomass beyond what is needed to maintain current population size If a fishery only catches the surplus production, then the population size remains If a fishery catches more, then the population shrinks If it catches less, then the population grows

Surplus Production Implications Surplus production has a maximum at about half of unexploited population size B∞ Keeping a population at 0.5 B∞ allows catching MSY forever A population is kept stable if the fishing rate F equals the intrinsic growth rate rt MSY is reached at ½ B∞ and ½ rmax Thus, MSY is reached at Fmsy = ½ rmax

New Approaches to Estimate MSY

MSY from Catch and Resilience For a population to sustain a history of output such as catch, it needs to have had a certain size and productivity If you know the time series of annual production (biomass taken out for human use), and you know the productivity of the species, then you can calculate biomass and reference points

Catch-MSY Method Martell & Froese 2013 Output of the Catch-MSY method showing “viable” pairs surplus production rate r and unexploited biomass k for North Sea cod. The red line indicates all r-k pairs that would result in the same estimate of MSY; the red circle indicates the geometric. While the estimate of MSY is robust, the geometric mean r = 0.24 depends on the lower bound for r.

New CMSY-Method in prep. Same approach as in Catch-MSY New, objective approach to determine rmax This results in surprisingly good estimates of biomass time series, Bmsy and Fmsy Formal Bayesian approach under development

Herring in the Gulf of Riga I 1) assumed r-k space 3) < 1% outliers in k 2) rmax in upper half 4) minimize SE of MSY 4-step zoom-in on area used to estimate geometric mean r, k and MSY

Herring in the Gulf of Riga II Fisheries reference points MSY (bold red line in upper left graph), Fmsy = 0.5 r and Bmsy = 0.5 k

Herring in the Gulf of Riga III Blue lines are prior biomass windows, medium resilience is prior for r. Red line is observed Biomass, black line predicted biomass, with 5th and 95th percentile. Required data are catch.

Herring in the Gulf of Riga IV Catch/biomass ratio u as proxy for F. Dotted line is umsy. Black line is predicted, red line is observed.

Herring in the Central Baltic Better fit possible by replacing defaults with “informative priors”.

North Sea Herring

Safe biological limits

The Past Common Fisheries Policy (until 2013) Apply a precautionary approach to fishing Keep fish stocks within safe biological limits

Safe Biological Limits Conceptual drawing of the hockey stick relationship between spawning stock size and recruitment. SSBlim marks the border below which recruitment declines, SSBpa marks a precautionary distance to SSBlim, and 2 * SSBpa can be used as a proxy for SSBmsy, the stock size that can produce the maximum sustainable catch. (Froese et al. submitted)

Status of European Stocks Extending the trends in the last 3 years for the 95% confidence limits… SSBpa UNCLOS UNFSA Based on the ICES Stock Summary database 10/2013 with data for 45 stocks. Update of Froese & Proelss 2010

Quality of Scientific Advice Fisheries science holds that mortality caused by sustainable fishing (Fmsy) should be less than natural mortality (M) caused by e.g. predation, diseases, natural hazards or old age Doubling mortality reduces life time and reproductive phase by half and also reduces average size and fecundity However, in 29 of 38 stocks (76%) with available data, the ICES estimate of Fmsy exceeded M, on average by 62% (Froese et al. submitted)

Fishing Mortality may be Higher True F/Fmsy may be higher because of unrealistically high Fmsy in 76% of the stocks Based on the ICES Stock Summary database 10/2013 with data for 45 stocks (Froese et al. submitted)

Quality of Scientific Advice ICES provides estimates of the border of safe biological limits (SSBpa). Below SSBpa recruitment may be reduced and the stock is at increased risk of collapse In 14 of 43 stocks (33%) with available data, the ICES estimate of SSBpa fell below the median estimate of three independent scientific methods.

Hake Southern Stock Froese et al. submitted

Underestimation of Safe Biological Limits SSBpa ICES three independent methods Analysis of stock-recruitment data for North Sea Doggerbank Sandeel (san-ns1), with three different methods. [S-R_HS_5_san-ns1.r] (Froese et al. submitted)

Stock Biomass may be Lower True SSB/SSBpa may be lower because of unrealistically low SSBpa in 33% of the stocks Based on the ICES Stock Summary database 10/2013 with data for 45 stocks (Froese et al. submitted)

Common Sense Rules for Ecosystem-based Management Only catch fish for direct human consumption Only catch species with high resilience Do not damage the ecosystem Take less than nature Let fish grow and spawn before capture

Size Matters (Froese et al. 2008, Froese et al. in prep) Three important points in the life of species with indeterminate growth: Length at maturity (Lm90) Length Lmax dW/dt where growth is maximum Length Lopt where cohort biomass is maximum

Natural Selection “Economizes” Organisation of Reproduction If reproduction happens when production of tissue is maximum Lm90 <= Lmax dW/dt (= in semelparous, < in iteroparous) Lm90 <= Lopt (then topt = generation time) Lmax dW/dt = Lopt (then most offspring are produced when production of tissue is maximum)

Basic Equations 𝑁 𝑡 = 𝑁 0 𝑒 −𝑀 𝑡

Economizing Reproduction Life history strategies for the timing of reproduction: A) semelparous, B) iteroparous with parental care, C) broadcast spawners. Note: Blue line is not to scale. Froese and Pauly 2013

Tradeoff between generation time and peak fecundity Froese et al. in prep.

Timing of spawning Based on 232 studies. Froese and Pauly 2013

Size Matters! Ll Lm90 Biomasse of a cohort (e.g. cod) vs length. Maturity is reached at Lm90 = 59 cm. Maximum growth and high fecundity is reached at Lopt = 86 cm. However, legal fishing starts at Ll = 35 cm. Froese et al. 2008

Fishing with Fmsy starting at Ll will not rebuild the stocks Lm90 Cohort biomasse (e.g. cod) without fishing (bold curve) and with F = Fmsy fishing Starting at legal length (dotted curve). Froese et al. 2008

Fishing with F=M starting at Lcopt rebuilds the stock Large biomass (~ 1.2 Bmsy) Higher catch Lower cost Lm90 Unexploited cohort biomass (bold curve), with Fmsy –fishing (dotted curve), and with F=M fishing starting at Lcopt (dashed curve), so that the mean length in the catch and In the exploited part of the stock equals Lopt. Froese et al. in prep.

Impact of Fishing on Size Structure Length-frequency without fishing (bold curve), with F = Fmsy fishing after Ll , and with F = M Fishing after Lcopt. With Lcopt fishing all fish reach maturity and about 2/3 reach Lopt. With Fmsy fishing after Ll , only 2/3 reach maturity and only 1/3 reach Lopt. Froese et al. in prep.

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