STRIPED BASS STOCK ASSESSMENT UPDATE - The Fisherman

STRIPED BASS STOCK ASSESSMENT UPDATE

The Atlantic States Marine Fisheries Commission (ASMFC) will convene this week at the Westin Crystal City hotel in Arlington, VA. Starting at 10:15 a.m. on Tuesday, April 30, the Atlantic Striped Bass Management Board will discuss and take action on the latest Atlantic Striped Bass Benchmark Stock Assessment.

There’s been a lot of action and reaction leading up to this important meeting in Virginia this week that pertains to the recreational fishing community and the future conservation efforts on striped bass.

VIRGINIA VOTES TO CLOSE TROPHY STRIPER SEASON
On April 23, the Virginia Marine Resources Commission voted unanimously (7-0) to enact an emergency closure for the spring recreational striped bass trophy season. Virginia’s decision comes following the recent scientific assessment of striped bass that shows the striped bass population has been below the sustainable threshold for the past 6 years and overfishing has been occurring since 2010.

“Virginia has always been a conservation leader, and this is a time to step up. The recent stock assessment shows that early action is needed to slow the decline and restore this fishery to sustainable levels,” Virginia Marine Resources Commissioner Steven G. Bowman said. “I am proud of the swift action taken by the Commission.”

The emergency measure will eliminate the spring striped bass trophy season in the Bay from May 1 through June 15, the Coast from May 1 through May 15, and the Virginia tributaries to the Potomac River from April 29 through May 15. Starting May 16 through June 15 fishermen will be able to catch and keep two striped bass from 20 to 28 inches.

“There has to be a starting point for conservation,” Commissioner Bowman said, while adding “However, we cannot act alone. We also need swift and lasting conservation measures enacted by the Atlantic States Marine Fisheries Commission (ASMFC).”

“ASMFC should incentivize and encourage other states to follow Virginia’s lead and take action this fishing season,” Bowman added.

STRIPED BASS TC RECOMMENDS 35-INCH MINIMUM
In a memorandum from the ASMFCs Atlantic Striped Bass Technical Committee (TC) to the Atlantic Striped Bass Management Board (Board) dated April 22, 2019, the TC made their recommendations for the reduction in harvest required to achieve F threshold and F target in 2020, along with examples of the recreational options needed to achieve those reductions.

At its February 2019 meeting, the Atlantic Striped Bass Management Board tasked the TC with providing the Board with a report that shows the reductions in harvest needed to reduce F to F threshold (0.24) and F target (0.197) and also providing one example of recreational bag and size limit combination (if necessary, seasonal restrictions) needed to achieve these conditions a) on the coast and b) in the Chesapeake Bay and report back to the Board at its May meeting.

The TC found that in order to have a 50 percent chance of being at or below the F threshold (F=0.240) in 2020, removals for 2020 needed to be 7.1 million fish. This is approximately equal to total removals in 2017, and a 26 percent increase from 2018 levels. This assumed that 2019 removals were equal to 2018 removals. Using the most recent 3-year average resulted in very similar results: removals to achieve the F threshold needed to be 7.0 million fish, a 1 percent decrease compared to 2017 and a 24 percent increase relative to 2018.

In order to have a 50 percent chance of being at or below the F target (F=0.197) in 2020, removals for 2020 needed to be 5.9 million fish. This is a 17 percent reduction from 2017 levels and a 5 percent increase from 2018 levels. This assumed that 2019 removals were equal to 2018 removals.

For those speculating on what those measures might be, the TC developed an example management change for the ocean recreational fishery and for the Chesapeake Bay (Bay) recreational fishery that would achieve a 17 percent reduction in total recreational removals (harvest and dead discards) relative to 2017 to reach F target. The TC assumed commercial removals would also be reduced by 17 percent through other management actions, so the reduction in total removals would be enough to bring F to the target.

Since the ocean is already at a one-fish bag limit and fishing seasons vary so much along the coast, the TC only looked at a size limit analysis for the ocean. For the Bay, a reduction in bag limit resulted in a greater than 17 percent reduction, so it was not included here. A season analysis was conducted for the Bay that resulted in several options for reducing the recreational season and achieving the required 17 percent reduction. Due to the TC’s request to see additional data on the daily catch rate assumptions for that analysis, and for simplicity and ease of comparison with the ocean, only the size limit analysis is included here.

For this analysis, the TC used MRIP length frequency data from 2016 and 2017. In 2020, the 2014 and 2015 year classes will be the same age as the 2011 year class was in 2016 and 2017, so the TC believed that those years would be most representative of the size structure of the population in 2020. Maryland and Virginia currently have different size limits within the Bay, so separate analyses were conducted for each state to achieve a 17 percent reduction within the Bay. In 2016 and 2017, Maryland’s minimum size was 20 inches and was decreased to 19 inches in 2018. As 19 inch fish were not fully represented in the 2016-2017 harvest length frequency, the proportion of 19 inch fish in the harvest was estimated as the average proportion in the harvest from 2000-2014, when the minimum size was 18 inches.

The TC concluded that in the ocean (which includes ocean waters from Maine – North Carolina and non-Chesapeake Bay inland waters like Delaware Bay and Long Island Sound), the current minimum size limit is 28 inches. In order to reduce total removals by 17 percent, the size limit would need to be increased to 35 inches. This analysis assumed that current non-compliant harvest (harvest of fish smaller than the current size limit) would still occur. As with any increase in minimum size, dead releases would be expected to increase as anglers would have to release fish that were no longer of legal size.

Under the 35 inch size limit, dead releases are expected to increase by 3 percent in the ocean. This increase is more than offset by the reduction in harvested fish. A 17 percent reduction is estimated if Maryland raised the minimum size limit from 19 inches for the summer/fall season to 21 inches. In Virginia, an 18 percent reduction is estimated if the 20-inch minimum size limit is increased to 22 inches. Under these scenarios, dead releases are expected to increase by 4.3% for Maryland and 3.5% for Virginia, but again, the increase is offset by the reduction in harvest.

ASMFC proceedings will be broadcast daily via webinar beginning April 29 at 1 p.m. and continuing daily until the conclusion of the meeting (expected to be 12:15 p.m.) on Thursday, May 2nd. The webinar will allow registrants to listen to board deliberations and view presentations and motions as they occur. No comments or questions will be accepted via the webinar. Go to –https://attendee.gotowebinar.com/register/1041506190356646145 – to register.