Chesapeake Bay Program A Watershed Partnership Date: Location: Time: LivRAW Meeting Tuesday, February 19, 2008 Chesapeake Bay Program Office Joe Macknis Memorial Conference Room (Fish Shack) 410 Severn Avenue, Annapolis, MD 10:00 am - 12:30 pm Minutes Attendance: Name Affiliation Email Address and Phone Number Bob Wood (co-chair) NOAA bob.wood.@noaa.aov (410) 226-5193 Peter Bergstrom (co-chair) NCBO Deter.berastrom@noaa.aov (410) 267-5665 Nancy Butowski DNR n butowski(Žd n r. state. md. us (410) 260-8268 Carlton Haywood (phone) ICPRB chavwood@icDrb.ora (301) 984-1908 ext. 105 Rob Latour (phone) VIMS latour@vims.edu (804) 684-7312 Jim Uphoff MD DNR iuDhoff@dnr.state.md.us (410) 643-6785 ext. 106 Tom Parham (phone) MD DNR Darham@dnr.state.md.us (410) 260-8633 Marek Topolski MD DNR mtoDolski@dnr.state.md.us (410) 260-8263 Xinsheng Zhang NOAA xinshena.zhana@noaa.aov (410) 226-5193 ext. 181 Heath Kelsey NOAA heath. kelsev@noaa.aov (410) 226-5193 Jennifer Greiner FWS areiner.iennifer@eDa.aov (410) 267-5783 Derek Orner NOAA derek.orner@noaa.aov (410) 267-5666 Krystal Freeman (staff) CRC freeman.krvstal@eDa.aov (410) 267-9830 Action Items: ~~~ Carlton Haywood, Bob Wood and Peter Bergstrom will work together to develop a proposal for Mike Fritz and Jennifer Greiner to review concerning the development of a workshop to define a restored Chesapeake Bay. ~~~ Carlton Haywood and Tom Parham will form a steering committee for the proposed joint MASC/ LRSC workshop. Model Suspension Feeders: Rob Latour Title: Modeling Atlantic menhaden in support of nutrient and multispecies management ------- http://archive.chesapeakebav.net/calendar.cfm?EventDetails=9320&DefaultView=all&R equestDate=02/04/2008 Status: Two years into the three year program Project Objectives: 1) To conduct a stock assessment for Atlantic menhaden in the Chesapeake Bay 2) To conduct a diet and feeding study to quantify menhaden prey selectivity and constrain consumption and excretion rates as functions of individual size, prey concentration, and fish density 3) To perform initial estimates of seasonal and annual menhaden population consumption of plankton in the Chesapeake 4) To conduct a multi-layered modeling analysis of the role of menhaden in both nutrient and fisheries management in Chesapeake Bay 5) To compare rates of menhaden consumption to those of other suspension feeders Project Details and Findings: 1. a metapopulation simulation model for Atlantic menhaden was created in an attempt to estimate abundance on a regional basis 2. the model is a spatially implicit age-structured statistical-catch-at-age model that reflects three sub stocks - northern, mid-Atlantic, and southern 3. the simulation model was used to generate data from known parameter values 4. an estimation model of the same underlying structure was then fitted to the simulated data to estimate leading parameters 5. the estimation model was able to estimate stock productivity parameters well, but it could not resolve the stock proportion parameters (i.e., proportion of total stock in each area). This is because the available coast wide data does not contain information about movement of Atlantic menhaden 6. obtaining estimates of Atlantic menhaden abundance on regional spatial scales by modifying the current stock assessment modeling framework may not be possible - more experimentally derived approaches may be most appropriate Discussion/ Concerns: 1. According to model simulations, menhaden catch declined along with a decrease in fishing effort in Chesapeake Bay. The decline in fishing effort could have been due to a menhaden population decline or changes in management of the fishery. (related objective: #1) 2. Chesapeake Bay menhaden abundances has been known to be decreasing since the 1980's but simulation model results did not show this decline . (related objective: #1) 3. The adult menhaden data used in this model comes from a single pound net survey. Thus the current model is not able to show regional changes. It has been suggested that model data be supplemented with trap net bait fisheries information. However, there are unresolved issues equating fishing effort between ------- the different catch methods. Even with additional data, it will still be difficult to separate menhaden sub-populations, (related objective #1) 4. It was suggested that the weighting of the age structure in the model is masking other signals that could be observed within the population. Population age structure is weighed heavily in this model because of menhaden life history. Older fish migrate north where there are fewer sampling sites. The current model assumes the older fish are not represented in the samples because they are not surviving; however it is more likely that available sampling sites do not encompass the entire range of the species. This is an artifact of using fishery dependant data and that the fishery is concentrated in the center of the species range, (related objective: #4) 5. York River water experiments showed that juvenile menhaden could digest plankton but age 1 and older fish can not. Menhaden are not passive feeders; they are visually selective. This means that they are not as effective at nutrient removal as shellfish, (related objectives: #2 & #5) Conclusions: This research project has not been able to identify a Chesapeake Bay sub- population of menhaden. However the role of menhaden in the reduction of nutrients is better understood. Further menhaden research will need to focus on experimentally derived information to assess the menhaden population as this program is in its final year. Current population models are limited by the spatial resolution of available data. Proposed MASC/ LRSC Workshop Discussion: Carlton Haywood Many believe that there is a need for a vision of what living resources in the restored bay would look like to motivate management action and measure progress. Currently Bay Program restoration efforts are driven by water quality because changes are quantifiable and goals for improvement have been established. If well defined, quantifiable goals for living resources can be established and the Program Managers would be more likely to focus on them. In order to define this vision, and inspire more living resource based management approaches, Carlton Haywood is proposing conducting a joint MASC/ LRSC workshop later this year. This workshop would engage Bay Program partners and academia to define what is a restored Bay and what needs to be done to achieve that defined status. Currently there is an effort to combine Ecosym/ Ecopath with the Bay Program water quality models. Combining the models may reveal water quality alone is not enough to restore the Bay. This may be a good approach to defining what a restored Bay is. The status of linking the two models should be known before setting a date for this workshop. Defining a restored Chesapeake Bay will be based on people's mental images; the models will be used to explore if achievement of these visions is possible. It was suggested that there may be some useful information in the STAC Chesapeake Future's Report and the 2020 Land Use Project which could be incorporated in this workshop. It was suggested that a discussion of social goals would be an important part ------- of this workshop. A steering committee needs to be formed and develop a proposal for this workshop. The scope of this workshop must be narrowly defined in a timely manner. Tom Parhan and Carlton Haywood volunteered to lead this effort with input from Peter Bergstrom and Bob Wood. Re-Organization Discussion: Peter Bergstrom How can we be sure to solidify the connections among LivRAW TMAW and MASC? A joint workshop semi-annually to foster communication between LivRAW and TMAW may be what is needed to solidify connections and coordinate the work plans of the two groups. Next LivRAW Meeting is TBD Adjourned ------- |