Striped Bass Decline
June 06, 2005
Striped bass decline is in both numbers and in size, according to a 2004 Internet survey of recreational anglers from Maine to North Carolina conducted by the nonprofit Stripers Forever (stripersforever.org). The combined results of fewer fish and small size caused the responding anglers to decide that the quality of striper fishing was worse in 2004 than at other times within the last five years. In 2003 a similar group answering the same survey reported that fishing had improved only slightly over the past five years.
Stripers Forever president Brad Burns says the recent survey results should come as no surprise "since bigger commercial catch limits, including a 40 percent increase in the coastal commercial quota just last year, have consistently been put in place by the Atlantic States Marine Fisheries Commission (ASMFC), which manages the striped bass fishery all along the Atlantic coast, over the protests of recreational anglers. In addition, fisheries scientists are reporting reduced survivability of young striped bass in Chesapeake Bay, the fish's prime breeding and nursery grounds, due to diseases that are affecting a large percentage of young stripers."
The Stripers Forever Internet surveys are not scientific, but they may show a trend in public opinion among sport fishers, one that indicates East Coast striped bass populations may not be faring as well as they have in the past five years and that more bad news could lie ahead.
If there is a decline, especially in older stripers, the causes may be more complex than just angling and commercial harvests. For instance, there are indications that over-harvest of menhaden populations, and a long-term downturn in menhaden reproductive recruitment, in the Chesapeake Bay may be causing declines in that prime striper forage base. Also, acid precipitation in the bay watershed has for decades contributed significantly to bay ecosystem problems, as has eutrophication of bay waters caused by massive nutrient migration from agriculture and other man-made sources.
Excessive harvest of larger (older aged) striped bass by sport fishers also remains a question, especially off the North Carolina coast at Diamond Shoals, where the large stripers stage in late fall before heading out to the Gulf Stream for winter. And undocumented commercial bycatch of older age stripers continues in those Gulf Stream wintering grounds, where management controls and enforcement are virtually nonexistent.
It may also be helpful to note that, according to Massachusetts's 2003 net surveys and modeling of harvests on stripers in its waters, there were 402,201 (over 5.1 million pounds) fish taken by recreational fishermen and 55,439 fish (1.1 million pounds) taken by commercial fishermen. Equally important to the mortality picture was death from capture and release: 344,000 fish by recreational fishers and 8,000 fish by commercials. The capture-and-release mortality is so high because the number of sport fishers catching and releasing under-legal-size bass is so high.
The Massachusetts official 2003 striper summary is this: "Total losses due to recreational fishing (including release mortality) were 745,758 fish weighing 7 million pounds. Combined losses were 810,381 fish weighing 8.1 million pounds, which reflects a 1.3 percent decrease in numbers lost and an 11 percent decrease in weight lost compared to 2002 (821,242 fish; 9,194,902 pounds) The majority of losses, 92 percent by number and 86 percent by weight, was attributed to the recreational fishery." (To review the 2004 data and estimates go to www.mass.gov/dfwele/dmf/recreationalfishing/stripedbass.html/.) Be sure to read the management section and the section about food preferences for stripers by season.
Striped bass populations are cyclical. Here's how cyclical from the management report: "Striped bass populations have a history of periods of abundance interspersed with periods of scarcity. A major coastwide reduction in abundance occurred at the end of the 19th century. No catches of stripers were reported north of Boston for 30 years after 1897. Populations had recovered somewhat by 1921, and an unusually successful year of reproduction in 1934 was followed by 6 years of markedly increased abundance. Great numbers of juvenile fish were recorded in Massachusetts waters in the mid-1940s, and high numbers of increasingly larger individuals followed for a period of years."
The report goes on to trace following cycles, up and down, with a nadir in the early '80s followed by rebuilding of stocks through the '90s under restrictive federal and state regulatory harvest managements (see chart). We are currently at one historic high in striped bass populations, and the report makes it clear that the Chesapeake Bay nursery is critical to striped bass populations on the East Coast.
And here is what the Striped Bass Technical Committee for the Atlantic Striped Bass Management Board of the Atlantic Fisheries Commission says:
"Stock size: The estimate for total abundance for January 1, 2004 is 56.7 million age-1 and older fish due to the strong 2003 age class. This estimate is about 11 million fish higher than the average stock size for the previous five years and 23.8% higher than the 2003 abundance."
"Spawning Stock Biomass (SSB): The female spawning stock biomass for 2003 is estimated at 30 million pounds, which is above the recommended biomass threshold of 28 million pounds (12,726 MT). However, most Technical Committee members expressed concern over the current estimates of spawning stock biomass and hence the conclusions from these estimates.
"Recruitment: Recruitment of the 2003 cohort for all stocks combined is 21.6 million age-1 fish and the highest observed in the time series. Preliminary survey indices for young-of-the-year striped bass for 2004 in Chesapeake Bay indicate the 2004 year-class is of average strength."
The report states that fishing mortality jumped 77 percent between 2002 and 2003, but the scientists expressed reservations on that data and concluded that harvest increased but probably did not double. There was certainly over-harvest of stripers in 2003 compared to the scientific target. There is a question about over-harvest on larger striped bass.
Based on its questions on fishing mortality rates, the technical committee recommended no liberalization of regulations in 2005.
In addition to the recreational and commercial harvest mortalities, the man-made ecological influences on all coastal fisheries are severe and far reaching. A new book Our Fragile Coastal Fisheries by Don Phillips explains just how severe and complex these problems are. (See Stream Watch in this issue.)
It can be purchased from Phillips at firstname.lastname@example.org or from Trafford Publishing at www.trafford.com/.