OVERVIEW OF NEW MANAGEMENT APPROACH FOR CRAB FISHERIES IN THE RUSSIAN WATERS

Transcription

1 OVERVIEW OF NEW MANAGEMENT APPROACH FOR CRAB FISHERIES IN THE RUSSIAN WATERS Sergey Bakanev The Polar Research Institute of Marine Fisheries and Oceanography (PINRO), Murmansk, Russia The 17th Russian-Norwegian Symposium

2 CRAB SPECIES OF RUSSIAN FAR EAST CRAB SPECIES OF BARENTS SEA Red king crab 43% of total catch (6.3 ktons) King crabs Paralithodes camtschaticus (red king / Kamchatka / краб камчатский) Paralithodes platypus (blue king / краб синий) Paralithodes brevipes (spiny brown king / краб колючий) Lithodes aequispinus (golden king / brown king / краб равношипый) Snow crabs Chionoecetes opilio (opilio /queen /snow / краб-стригун опилио) Chionoecetes bairdi (tanner / snow / bairdi / краб-стригун берди/бэрда) Chionoecetes angulatus (triangle tanner / краб-стригун ангулятус) Chionoecetes japonicus (red snow / краб-стригун красный) Other crabs Eriocheir sinensis (hairy mitten / Японский мохнаторукий краб) Erimacrus isenbeckii (Japanese horsehair / краб волосатый четырехугольный) Snow crab 32% of total catch (8.9 ktons) Pacific ocean

3 RUSSIAN CRAB FISHERY IN 2015 Total catch is ~ 65 ktons Barents sea 23 % of total catch (15 ktons) Far East 77 % of total catch (50 ktons) CRAB SPECIES OF BARENTS SEA Red king crab 43% of total catch (6.3 ktons) Snow crab 32% of total catch (8.9 ktons) Pacific ocean

4 PREVIOUS MANAGEMENT SCHEME Biological objective is to prevent overfishing No explicit management strategy (no points and plans) Management mechanisms are regulation by TAC and technical regulation. TAC Technical regulation Permanent and temporary Current assessment Prediction of fishable stock biomass (FSB) Sex and size restrictions; Gear limitation; Season limitation; Area limitation TAC (proportion (%) of FSB ) There were no model assessment and prediction for the vast majority of stocks. Main assumption was prediction biomass is assumed to be equal of current biomass. So TAC of prediction year was a proportion (or percentage) of biomass for current year.

5 PREVIOUS MANAGEMENT SCHEME Prediction of FSB Healthy Management decisions Cautious Critical TAC % of FSB 5-20 % of FSB No TAC Additional technical regulations Season and area limitations close fishery

6 PREVIOUS MANAGEMENT SCHEME Pros and cons Simple and understandable approach for biologists, managers and stakeholders. Standard practice and procedures for national fishery management. Flexible conditions for experts and decision makers. Does not provide transparency and accuracy in determining TAC. No exploitation plans and management strategies. No common and widespread approaches (reference points, uncertainty consederations, risk analysis, precautionary approach, data availability categorization). In 2015 Federal Agency for Fisheries ordered to develop a document was subsequently named as Basics of fishery management for crabs and craboids.

7 BASICS OF FISHERY MANAGEMENT FOR PRIORITY CRABS AND CRABOIDS 23 authors from 5 institutes 4 priority species for 33 stocks Paralithodes camtschaticus (red king / Kamchatka / краб камчатский) Paralithodes platypus (blue king / краб синий) Chionoecetes opilio (opilio /queen /snow / краб-стригун опилио) Chionoecetes bairdi (tanner / snow / bairdi / краб-стригун берди/бэрда) Craboids (8 legs) Crabs (10 legs)

8 BASICS OF FISHERY MANAGEMENT FOR PRIORITY CRABS AND CRABOIDS Main aim of paper is development of management plans for each stock. There are several steps to implement plan: Data and methods analysis. Stock categorization according data availability. Selection of assessment approach, parameters, drivers and indicators. Evaluation of referents points and current state of the stock. Retrospective analysis and set of maximum variation of TAC for prediction years. The formulation of a long-term exploitation target and development of management tools.

9 BASIC ELEMENTS Main steps for plan implementation Qualitative indicators Reference points Quantitative indicators State of the stock Exploitation rate Size of the stock Data availability Aim of exploitation Yield maximization Sustainable production Stock recovering Harvest Control Rule Management plan Maximum variation of TAC (%) Technical regulation

10 Data availability Data-rich population BASIC ELEMENTS DATA availability levels First level Assessment is age- or size - structured, so needs time series of age and/or size data and can estimate changes in fishery characteristics over time and can estimate fluctuations in annual recruitment, and has direct information on the fishing mortality of each year class entering the stock Second level Assessment based on time series of catch and an abundance index to support application of a dynamic production model Third level Assessment based on empirical trends and/or indicators in relative stock abundance Data-poor population

11 BASIC ELEMENTS Indicators of state of the stock Indicators are defined as variables, pointers or indices of a phenomenon (Garcia et al. 2000). Typically, potential indices are grouped into 3 or 4 categories representing: Abundance Early season catch rate, survey counts, commercial fishing area Production Number of recruits, mean size, average maximum size, sex ratio in catches, proportion berried, density of larvae, condition factors, disease Fishing pressure Proportion immature in catch, total trap hauls (per area ground), incidental mortality (discards or other gears), landings alternative species, exploitation rate, proportion females in catch, proportion of catch taken during ovigerous period Ecosystem and environment Predator abundance, prey abundance, temperature indices, wind/current flows

12 индекс запаса, тыс.т BASIC ELEMENTS Reference points Target and limit (or buffered referents point as the upper border of the confidence interval of limit reference point). Methods of evaluations: 1) Assessment models ; 2) Percentiles of historical trends [Koeller et al., 2011; Буяновский, 2012].; 3) By experts based on subjective considerations Assessment of reference points by percentiles on the example of the dynamics of the index of blue crab stock in the Primorye subarea, and trends in the stock built over all (1) 5 and the last (2) years. The green line shows the value of the target value defined for 2014.; Red - the value of the limit point, defined for 2014, below which the fishery should be closed. Trend 1 - not meaningful; Trend 2 - significant.

13 BASIC ELEMENTS Harvest Control Rule (HCR) Traditional The Traffic Light color convention Proposed 4-colors scheme Critical Cautious Healthy Phase of the explosion of abundance E exploitation rate (coefficient): E lim limit; E tg target, E t, 50% - coefficient in prediction year, E t, 5%, E t, 95% - coefficient according to limits of confidence interval; FSB fishable stock biomass, FSB lim limit, FSB tg target, FSB t, 50% - prediction, FSB t, 5%, FSB t, 95% - upper and lower limits of confidence interval; FSB lim-t limit value for excessively increasing stock.

14 BASIC ELEMENTS Harvest Control Rule (HCR) Proposed 4-colors scheme Dynamics of the abundance of the introduced species during acclimatization Karpevich, 1975) Abundance Receiving capacity of the basin The area of the FSB>K (carrying over-population capacity) Critical Cautious Healthy Phase of the explosion of abundance I II III IV V Phases of acclimatization E exploitation rate (coefficient): E lim limit; E tg target, E t, 50% - coefficient in prediction year, E t, 5%, E t, 95% - coefficient according to limits of confidence interval; FSB fishable stock biomass, FSB lim limit, FSB tg target, FSB t, 50% - prediction, FSB t, 5%, FSB t, 95% - upper and lower limits of confidence interval; FSB lim-t limit value for excessively increasing stock.

15 BASIC ELEMENTS State of the stock Newly exploited status for stocks which recently exploited for the first time or after longtime fishery closing. Critical Cautious Healthy Prosperous (increasing) stock is above target reference point and clear tendency of growing. In case when we have some negative tendency of very high abundance so called overpopulation, state of the stock is defined as excessively increasing stock. Stable stock is above target reference point and has no clear tendencies in dynamics. Reducing stock is between target and limit reference point with negative dynamics. Recovering stock is between target and limit reference point with positive dynamics. Depressive New exploited Stable Prosperous Phase of the explosion of abundance Depressive stock is under limit reference point. Undefined no useful information concerning exploitation rate and biomass level.

16 BASIC ELEMENTS Maximum TAC variation achievement of year-to-year stability in TACs; avoid over- and under- estimation of TAC due to high uncertainty in particular year. Value of variation depends on state of the stock and based on biomass fluctuation Year -/+% of TAC ~ -/+% of FSB PERIOD FSB (ktons) Mean 14 Percent change (%) Recommendation: the TAC should not be changed by more than +/- 14% compared with the previous year s TAC.

17 BASIC ELEMENTS Aims and management plans Yield maximization; Achievement of year-to-year stability ; Stock recovering According to Quantitative Fisheries Stock Assessment book by Hilborn and Walters (1992)

18 SOME POINTS FOR CONCLUSION Besides a new approach the paper gives analysis of existing measures and Summarize information concerning crab fisheries over last 10 years. management actions. First global experience to reorganize the management approach in national fisheries policy. Paper can be use as background for complex rebuilding of fisheries management of all crabs. Management plan and other issues should be review every three year. Thank you!