States Marine Fisheries Commission
PUBLIC INFORMATION DOCUMENT
For Amendment 6 to the Interstate Fishery Management Plan For
ATLANTIC STRIPED BASS
Prepared by Robert Beal
Fishery Management Plan Coordinator
For a Print Version of this Document in Adobe PDF Format Go to the ASMFC web site
The Atlantic States Marine Fisheries Commission (Commission), is developing an amendment to its Interstate Fishery Management Plan for Atlantic Striped Bass (FMP)under the authority of the Atlantic Striped Bass Conservation Act (ASBCA). Atlantic Striped Bass management authority lies with the coastal states and is coordinated through the Commission. Responsibility for compatible management action in the Exclusive Economic Zone (EEZ) from 3-200 miles from shore lies with the Secretary of Commerce through ASBCA in the absence of a federal Purpose of the Public Information Document. The purpose of this document is to inform the public of the Commissions intent to gather information concerning the Atlantic striped bass fishery and provide an opportunity for the public to identify major issues and alternatives relative to the management of Atlantic striped bass. Input received at the start of the amendment development process can have a major influence in the final outcome of the Amendment. The purpose of this documentis to draw out observations and suggestions from these groups, as well as any supporting documentation and additional data sources. To facilitate public input, this document provides a broad overview of the extent of the issues facing the Atlantic striped bass population and fishing industry, as well as a wide range of potential management measures which may impact the stock and dependent fisheries.This document identifies 7 specific issues on which the Commission is seeking public comment, however the underlying question for public comment is:
"How would you like the striped bass population and fishery to look in the future?" Please provide any general comments on the striped bass population or striped bass management as well as any comments that are specific to the issues listed later in this document.
The publication of this document and announcement of the Commissions intent to amend the existing Atlantic striped bass FMP is the first step of the formal amendment process. Following the initial phase of information-gathering and public comment, the Commission will evaluate potential management alternatives and the impacts of those alternatives. The Commission will then develop a draft amendment to the FMP with the preferred management measures identified for public review. Following that review and public comment, the Commission will specify the management measures to be included in the new amendment. A tentative schedule for the completion of Amendment 6 is included in the back of this document, please note that these dates may change if the Management Board or Technical Committee needs additional time to complete any of the listed tasks.
This is your chance to tell the Commission about changes observed in the fishery, things you feel should or should not be done in terms of management, regulation, enforcement, research, development, enhancement, and any other concerns you have about the resource or the fishery as well as reasons for your concerns.
Atlantic striped bass have been managed by the states under the Commissions fishery management plan and amendments since the early 1980s. Striped bass are currently managed under Addendum IV to Amendment 5 to the FMP. Amendment 5 includes goals to prevent overfishing, maintain a sustainable spawning stock biomass, achieve equitable management measures among jurisdictions, and identify critical habitats.
Amendment 5 also includes management requirements for the commercial and recreational striped bass fisheries. The management requirements for the recreational fishery are a 20-inch minimum size in producer areas and 28-inch minimum size in coastal areas. A two-fish bag limit along the coast and in the Chesapeake Bay (Tables 3- 5 Amendment #5). The Amendment includes tables that allow jurisdictions to alter these preferred measures, while maintaining the conservation goals of the Amendment.
The management approach constrains the commercial fishery by the same size limit regime established for recreational fisheries in producer and coastal areas. In addition, commercial fisheries in each state are limited to a flexible statewide quota. The state commercial quotas are based on state allocations during the period 1972-1979 (with the exception of the Chesapeake Bay which is calculated for recreational and commercial fisheries based on annual estimates of achieving a 23% exploitation rate (F=0.28) based on annual tag and return studies).
From 1995 through 1999, all of the states that are included in the Atlantic Striped Bass Management Plan implemented management programs that are consistent measures with Amendment 5. A number of states implemented modified management based on conservation equivalency. For instance, some of the producer areas implemented an 18- inch minimum size limit with a shortened fishing season, or in the case of the Chesapeake Bay states, a reduced catch quota. Other states voluntarily implemented management programs that are more conservative than those required by the plan.
Based on the requirements in Amendment 5, the states developed striped bass management programs that changed annually from 1995 through 1998. In order to reduce the frequency of changes to the management program, the Management Board developed Addendum III to Amendment 5 to maintain the 1998 fishing regulations through 1999 and 2000.
During the two year period established in Addendum III (1999 and 2000), an addendum or amendment was to be developed to refine the management program detailed in Amendment 5. Amendment 5 includes interim reference points that may or may not be appropriate for the long- term management of striped bass. This addendum or amendment would have considered alternative reference points such as age-structure targets, biomass targets, and other fishing mortality targets. It was also intended to establish the virtual population analysis (VPA) as the basis for evaluating the management program (i.e., estimating fishing mortality and biomass).
However, Addendum III included a provision that if the 1998 fishing mortality estimate was significantly above the target, the states could take action in 1999 to reduce harvest to safe levels for the year 2000. The Management Board met on August 5, 1999 to review the results of the 1999 striped bass stock assessment. This assessment indicated that the 1998 fishing mortality on fully recruited (age 4 and older) striped bass exceeded the target and equaled the overfishing definition established in Amendment 5. Therefore, the Management Board decided that the management program for year 2000 needed to be altered to reduce fishing mortality.
In order to instruct the states on reducing the fishing mortality rate for year 2000, the Management Board developed Addendum IV. Under this Addendum the states were required to implement management measures to reduce the fishing mortality on striped bass age 8 and older by 14%. The Addendum also included the provision that allowed states that implemented management measures that were more conservative than the benchmarks in Amendment 5 to receive credit toward the required reduction. The states and jurisdictions are currently implementing these management programs.
The final provision contained in Addendum IV requires states to implement management changes during 2001 to reduce fishing mortality to the targets contained in Amendment 5 unless Amendment 6 is completed prior to January 1, 2001. Therefore, this Amendment is scheduled to be approved in October of 2000 in order to allow the states sufficient time to implement any necessary management changes by January 1, 2001.
Description of the Fishery Commercial Fishery
The commercial harvest of striped bass peaked at almost 15 million pounds in 1973. The harvest then declined by 77 percent to 3.5 million pounds in 1983. Since the reopening of the fishery in 1990, the landings have been allowed to slowly increase, peaking at nearly 6.5 million pounds in 1998 (Figure 1). The commercial landings have peaked at a lower level than the recreational landings, due to commercial landings being capped through quotas, while recreational landings are regulated by size/bag limits with no restriction on the total catch.
The predominant gear types in the commercial fisheries are gillnets, pound nets, and hook and line. Commercial fisheries operate in 8 of the 14 jurisdictions regulated by the Commissions FMP. Commercial fishing for striped bass is prohibited in New Jersey, Pennsylvania, Connecticut, New Hampshire, Maine and the District of Columbia. Massachusetts allows commercial fishing with hook and line gear only, while other areas allow net fisheries. The largest commercial landings are from Maryland, Virginia, Massachusetts, Potomac River Fisheries Commission, and New York (Table 1).
Since 1979, the first year sport harvest was surveyed by the Marine Recreational Fisheries Statistics Surveys, sport harvest has ranged from 28 to 73 percent of the total harvest. Sport harvest in weight of striped bass dropped from a high of over 6.5 million pounds in 1979 to 0.7 million pounds in 1989. Recent sport harvest has grown from a low of 2.2 million pounds in 1990 to a high of 15.9 million pounds in 1997. The sport landings dropped in 1998 to 12.9 million pounds (Figure 2).
In 1998, the states with the largest proportion of recreational harvest were Massachusetts, New York, Virginia, and Maryland. Recreational discards in 1998 were 15 million fish which resulted in a hooking mortality loss of an estimated 1.2 million fish. Discarded fish from Massachusetts and Maryland represent 65% of the total number of fish discarded (Table 2).
Status of the Stock
The estimated 1998 exploitation rate of fully recruited striped bass (ages 4 and older) was 29% (F=0.38), which exceeds the target exploitation rate of 25% (F=0.31) and equals the overfishing definition of 29% exploitation (Fmsy=0.38) (Figure 3). The plan calls for the Commission to manage the striped bass stock as a whole to achieve the target fishing mortality rate (which allows the fishing mortality on certain ages of fish to exceed the target, while fishing mortality on other ages may fall below the target (Table 3)). The average exploitation rate on age 8 and older striped bass is 33%, while the average exploitation of striped bass between the ages of 4 and 7 is 24%. The Management Board is specifically concerned with the increasing mortality of age 8 and older striped bass.
Total stock size increased slightly in 1998 to 36.5 million fish. However, stock growth appears to have stabilized, and there was a decline in the spawning stock biomass from 15 million pounds in 1997 to 14 million pounds in 1998. In addition, the exceptionally large 1993-year class and the above average 1996-year class may not be as strong as indicated by juvenile abundance index values (Figure 4.).
Since the overall fishing mortality (F) exceeds the target fishing mortality rate and equals the overfishing definition, the current regulations may not be sufficient to achieve and maintain management targets. Recent trends in stock growth and spawning stock biomass levels, coupled with the moderation of the 1993-year class by the fishery, indicate the stock growth is leveling off.
The population modeling tools used to estimate striped bass population characteristics are considered to be fairly accurate. However there is some variability associated with the model results. The estimates of 1998 striped bass fishing mortality were generated mathematically based on a VPA that used data collected through the end of 1998. The estimates of 1998 fishing mortality, overall biomass and, spawning stock biomass are likely to change slightly when the next assessment update is completed. Also, the estimate of 1999 fishing mortality rate will not be known until the summer of year 2000, and this number may be higher or lower than the estimate for 1998.
Public Comment Issues
Public comment is being sought on a series of issues that may need to be addressed in Amendment 6. The issues listed below are intended to focus the public comment and provide the Management Board the input necessary to develop a draft Amendment 6. The public is encouraged to submit comments on all of the issues listed below as well as any other issues that may need to be addressed in Amendment 6.
Issue 1. What are the appropriate management objectives for Amendment 6? The Commission is considering the following management objectives for Amendment 6 to the FMP and is seeking input on these and any others that may be raised.
A. Manage coastal striped bass fisheries under a control rule designed to maintain stock size at or above some predetermined biomass level, such as the biomass level associated with Fmsy or that associated with levels of fishing mortality lower than Fmsy.
B. Balance fishing mortality on age groups so that no age group is subject to disproportionate or high fishing mortality rates in order to maintain an age structure that enhances spawning potential.
C. Regulate coastal striped bass fisheries in member states waters and federal waters in a manner that maintains the biomass level at or above the reference biomass level.
D. Provide a management plan that strives, to the extent practicable, to maintain coastwide consistency to implement measures, but allows the states limited flexibility to implement alternative strategies that accomplish the objectives of the FMP.
E. Define and foster a quality recreational fishery, a stable charter boat fishery, and an economically viable commercial fishery.
F. Maximize cost effectiveness of current information gathering and prioritize state obligations in order to minimize costs of monitoring and management.
G. Adopt a long-term management regime which minimizes or eliminates the need to make annual changes or modifications to management measures.
Issue 2. Should the management program differentiate between coastal areas and producer
areas with dual size limit standards?
During the development of Amendment 4, which regulated the re-opening of the fisheries in 1990, the distinction was made between producer and coastal areas. The division into different management areas was accompanied by two sets of minimum sizes: 28" along the coast and 20" in producer areas. The justification for the split was the reduced availability of the larger fish within producer areas due to the migratory behavior of striped bass, which results in a net movement of larger fish out of the producer areas after the spawning period. In addition, the producer areas have traditionally harvested smaller fish and a decision was made to maintain these traditional fisheries.
Although the minimum size in most producer areas is 18" (taken with a penalty), the landings data from many fisheries (particularly recreational) suggests that fishermen are selecting for larger fish. The majority of the fish landed from the Chesapeake Bay recreational fishery in 1997 were 19-20" total length.
Migration of striped bass is linked to their sexual maturity and proximity to nursery areas. Due to the proximity of the Hudson River stock to the coastal area fishery, a large proportion of the fish from the Hudson River are less than the 28" minimum size. Also, a smaller portion of the fish from the Delaware and Chesapeake stocks entering the coastal fishery are under the 28" minimum. A change to a uniform size limit below 28" could increase the number of legal fish available to coastal fishermen. Maintenance of a distinction between coastal and producer areas also requires good information about migration rates in order to determine the availability of fish in different areas. Information on the abundance in each area is also required to determine quotas and develop benchmark overfishing criteria. The uncertainty in the migration parameters contributes to increased risk of miscalculating quotas and overfishing definitions.
In recent years, from 65% to 85% of the recreational harvest of resident striped bass has been below 24 inches total length. On average, for comparable season lengths and creel limits, an increase in the minimum size of striped bass from 18 to 24 inches total length may decrease the number of striped bass harvested in the Chesapeake Bay recreational result in a large increase in discard mortality of sub-legal striped bass in the Chesapeake Bay. Clearly, there is a significant economic investment on the part of the recreational striped bass industry. An increase in the minimum size limit to 24 inches may negatively impact the growing economic gains associated with this valuable recreational fishery.
A varying percentage of the Atlantic striped bass stocks are part of a coastal migratory group which generally spends late May through March outside of producer areas. Consequently the size structure of fish generally present within the producer areas is skewed towards the smaller, non-migratory, resident component of the stock. Any increase in the minimum size would reduce the amount of fish available to the fisheries within producer areas. An increase in minimum size would also reduce the number of cohorts vulnerable to fishing. Since quotas within producer areas vary depending on incoming recruitment strength, the reduction in the number of available cohorts would result in more volatile changes in annual quotas. The buffering effect from having multiple cohorts contribute to the annual quota would be reduced.
The Management Board is currently guided by the information on exploitation and stock structure that is developed through the VPA. In 1998, the VPA generated information indicated that the exploitation levels in 1998 have exceeded the exploitation targets and reached the overfishing level that was established in Amendment 5. This relatively high exploitation level was achieved even though some of the states with large striped bass fisheries didnt "fully implement" the dual size limit established in Amendment 5. Specifically, some of the key coastal state, such as New York and Massachusetts, limited their recreational fishermen to one fish, when Amendment 5 allows the coastal states implement a two fish recreational bag limit. Further, the Chesapeake Bay states have never fully landed their model-generated quotas.
Simply stated, there are indications that the even with states being more conservative
than required by Amendment 5 the exploitation rate on the striped bass populations may be
Additional issues: The Chesapeake Bay fisheries account for the largest percentage of the harvest of striped bass. An increase in minimum size may result in a re-allocation of the resource to coastal users. Since the producer area catch would likely decrease with a larger minimum size, more fish and potentially greater catch would be available to coastal fisheries.
Issue 3. What is the fair and equitable allocation of the striped bass resource between
jurisdictions and between user groups?
When Amendment 5 was developed, one approach for management was to develop quotas for user groups from projections based on total stock size estimated using the VPA. This approach would require the Management Board to allocate the overall quota between states or regions and possibly user groups. This approach has not been adopted by the Board, primarily because the fisheries have been operating at a status quo level since the VPA was completed. The VPA can currently be used to develop a series of quotas or allocations based on the decisions of the Management Board.
Option 1 (Separate coastal and producer area TACs): Divide the total allowable catch (TAC) between coastal and producer areas based on migration pattern(s) of striped bass. Allocation between producer areas and then between states could be based on average catch (including recreational release estimates) in certain reference years or other factors (possibly, relative fishing effort, relative magnitude of production, relative area of abundance, etc.). States then decide internally how to divide between user groups and monitor quotas.
Option 2 (Develop an overall TAC that does not distinguish between coastal and producer areas): Base total state allocation on average catch (including recreational release estimates) in certain reference years, ignoring division between coast and producer areas (annual allocations would change according to a states chosen size limit irrespective of geography). States then decide internally how to divide between user groups and monitor quotas.
Option 3 (overall TAC divided equally among states with similar size limits): Ignore historical harvest records by dividing the TAC equally among states that are exploiting similar age classes of fish. State quotas could then be adjusted by negotiation at the Management Board and Advisory Panel level.
Option 4 (status quo allocation of the striped bass resource): The management of the coastal striped bass recreational fishery would continue through a series of revised biological reference points (exploitation rates, biomass targets, etc.). The coastal commercial fisheries would have an allocation of the available TAC that is divided among states based on historic landings. The Chesapeake Bay commercial and recreational fisheries would be managed based on an annual baywide quota that is established to achieve a certain exploitation target.
Issue 4. What are the appropriate targets and reference points for the striped bass fishery? A number of approaches could be used to manage the striped bass population and fisheries in the future. The details of the approach that is to be used depends on the management objectives. The Management Board is interested in receiving comment on the objectives that the public would like to see achieved. Striped bass could be managed to achieve the following objectives:
A. Manage for maximum sustainable yield, which would result in a large proportion of the catch being small fish.
B. Manage for high numbers of large fish, which would require very low exploitation rates to allow the population to fully expand.
C. If the current environmental conditions cannot support the current abundance or future levels of striped bass, the exploitation rate may need to increased to reduce the overall population size of striped bass.
The level of exploitation to sustain biomass levels over the long term was calculated by the technical committee to equal 29% annual exploitation under the present regulations. The Management Board adopted the 29% exploitation rate as an overfishing definition and an exploitation target of 25%. The exploitation target was chosen to reduce the risk that overfishing would occur given the uncertainty in the estimates of the overfishing definition and annual exploitation estimates. The recent assessment in 1999 (for the 1998 fishing season) indicated that the exploitation rate on fully recruited striped bass was 29%, which exceeded the exploitation target and equaled the overfishing definition. On the long-term, the chosen exploitation target can be adjusted depending on the objective of management. If the intent were to allow the stock to recover to historic levels of large fish in a short time, it would occur faster with lower levels of exploitation. However, if the objective is to maintain a high level of yield while ensuring sustained recruitment, a moderate reduction in the present target is likely to be adequate. Other questions remain regarding ecosystem management. If the current system cannot support the current abundance or future levels of striped bass population, one way to reduce production would be to increase exploitation. Part of the answer depends on the objectives of management, keeping in mind that it is impossible to optimize several scenarios simultaneously.
As was mentioned above, the exploitation target can be adjusted depending on the management objective. Different exploitation target values would be necessary if the objective is high yield, historic levels of large fish, or to decrease striped bass biomass. Currently striped bass is being managed by exploitation target of 25% which is midway between the overfishing definition of 29% exploitation and 21% exploitation (which was an arbitrary half way point used to reopen the fishery in 1990). The Technical Committee thinks exploitation target should be relative to the overfishing definition, and not some arbitrary lower bound. One option would be to define the exploitation target as a percentage of the overfishing definition. Many of the federal overfishing definitions and targets use a target of 75% of the exploitation rate that supports maximum sustainable yield, currently the striped bass target is 76% of the exploitation rate that supports maximum sustainable yield.
The Board may want to consider alternative reference points. The current overfishing definition manages for maximum sustainable yield, with lots of small fish in the harvest. Other reference points, such as spawning stock biomass, or size limits/slot limits could be used to develop a population structure that will support fisheries for larger fish. The Board may also want to have other triggers besides exploitation. The Sustainable Fishery Act includes biomass that supports the maximum sustainable yield for management purposes. Triggers such as age structure of the spawning stock and young of the year indices could be used in addition to exploitation overfishing.
Issue 5: Should the current planning horizon for striped bass be changed?
The current planning horizon in striped bass management is one year. The short time frame requires policy changes within states on an annual basis and creates an unstable situation. State regulators would prefer coastwide striped bass management to occur in longer time periods, perhaps in 3-year increments. This would require setting up quotas for three years and reviewing the stock conditions annually to modify the quotas as needed. The benefits of such a system would be less time spent on policy development among and within states. A stable suite of regulations may also increase the chances of compliance by the fishing public. A three-year policy would not require projection of incoming striped bass recruitment beyond what was already in the system.
Also, a 3-year planning horizon will allow managers to use stock assessment estimates that incorporate the three previous years. The estimates of fishing mortality and stock biomass from the current assessment model have the greatest uncertainty for the most recent year. A longer planning horizon could use estimates with lesser uncertainty.
Issue 6: Should the EEZ be reopened to Atlantic striped bass fishing?
In 1989, federally controlled waters (beyond 3 miles from shore to 200 miles offshore, known as the Exclusive Economic Zone or EEZ) were closed to fishing or possession of striped bass, with the exception of a small corridor between Rhode Island and Block Island. Since the closure, the striped bass stocks have been declared restored and some recreational and commercial groups have requested reopening of all, or a portion of federal waters. Some states feel reopening is justified because of the recovered status of the stocks. Under one proposed option state jurisdiction and authority to manage striped bass would be extended from 3 to 12 miles with no increase in state quotas. (Note that in order to extend state jurisdiction and authority to 12 miles Congressional action is required.)
The arguments of limited extension of fishing beyond three miles come from the reality that water temperatures and bottom conditions along certain sections of the Atlantic coast attract striped bass further offshore. The advocates for a greater area opening argue that so long as total landed catch is controlled by the states quotas, size limits, and daily catch rates then there would be no impact from a limited extension of fishing to twelve miles. The arguments against further reopening are centered upon concerns that increased fishing effort might result from the increased area available for fishing.
Issue 7: What other issues should the Commission address through Amendment 6?:
|Schedule of Amendment Process||Stage Tentative Date*|
|Approval of Draft Public Information Document (PID)||March/April 2000|
|Public Information Hearings||April/May 2000|
|Approval of Public Hearing Draft of Amendment||6 June/July 2000|
|Hearing on Public Hearing Draft of Amendment||6 July/August 2000|
|Approval of Amendment 6 Annual Meeting||(Oct.) 2000|
|ASMFC Adoption Annual Meeting||(Oct.) 2000|
* The dates included in this table are tentative and subject to change.
Public Comment Opportunities and Deadlines
The Commission invites comment on this Public Hearing Document no later than Wednesday,
May 31, 2000. You may do so in one or more of the following ways:
1) Attend public hearings held in your state or jurisdiction;
2) Refer comments to your states member on the Atlantic Striped Bass Management Board or Advisory Panel, if applicable;
3) Mail, fax, or email written comments to the following address:
Fishery Management Plan Coordinator
Atlantic States Marine Fisheries Commission
1444 Eye Street NW, 6 th Floor
Washington, DC 20005
Phone: (202) 289-6400
Fax: (202) 289-6061
Table 1. State-by-State Commercial Landings of Atlantic Striped Bass
|State||Landings (number of fish)||Landings (Pounds of fish)|
* Potomac River Fisheries Commission
Table 2. 1998 Atlantic Striped Bass Landings, Discards and Discard Mortality from Recreational Fisheries
|State Recreational||Landings (number)||Recreational Discards (number)||Discard Mortality (number)|
Table 3. Age Specific Striped Bass Fishing Mortality for 1996-1998.