Signs of health from 4 species Indicators: If more improvement is made to the Chesapeake, it seems likely to be seen first in rockfish, crabs, shad and oysters.

On The Bay

October 16, 1998|By Tom Horton | Tom Horton,SUN STAFF

IF WE ARE to see any speedup in the improvement of the Chesapeake Bay's health, it seems likely to come first from individual species -- rockfish, crabs, shad and oysters. These species are used as four of the 12 key indicators in the Chesapeake Bay Foundation's recent State of the Bay Report.

For example, the health of rockfish, or striped bass, less than a decade ago would have been rated no more than 10 on a scale of 100, had the foundation done its report then. But this year rockfish got a 70, the highest ranking among a dozen indicators that range from wetlands to toxics to aquatic grasses.

Rockfish are a textbook case in managing a dramatic turnaround. Overfishing brought the whole East Coast population, 90 percent of which are born in the Chesapeake, near collapse by the early 1980s.

What followed was a politically courageous, five-year ban on catching them in Maryland. Bolstered by strong federal oversight that included authority to shut down a state's fishery, all the East Coast states followed with bans or dramatically curtailed fishing.

Sufficient money, federal and state, was available to do the scientific research needed to understand the population dynamics of rockfish, the kinds of fishing pressure they could and could not withstand.

Maryland's leadership was bolstered by monitoring, back to 1954, of the annual spawning success of rockfish. This data proved the fish were in unprecedented trouble, not just a natural down cycle.

Rockfish might not be quite back to Capt. John Smith's bay of 1607 -- the foundation's benchmark of 100 percent -- but they are close.

So why weren't they scored at, say, 90? Mainly because in the past year or so, significant numbers are turning up diseased and undernourished.

To Bill Goldsborough, the bay foundation's chief fisheries scientist, this raises a cautionary note regarding turnarounds in bay health.

You can get fairly rapid results from eliminating the most immediate cause of a species' decline -- like overfishing, Goldsborough says (banning DDT to revive bald eagles and ospreys comes to my mind).

But ultimately, if you don't bring back the larger ecosystem, the forests and wetlands and underwater grass meadows and oyster reefs that provided food and habitat, you run into limits on any species' potential to flourish.

These segments of the bay's health are going to be harder to move. With wetlands, rated at 43 percent of their 1607 status, it is considered a victory that the rate of loss has slowed considerably.

It would take an almost unimaginable effort to boost the wetlands index to 50 percent -- creating tens of thousands of acres. Submerged grass beds, water clarity and life-giving oxygen in the bay's deep waters are rated at 15 or lower of a possible 100.

The main thing depressing all of them is an overabundance of nutrients, nitrogen and phosphorus from sewage, farm runoff and air pollution.

Despite a lot of work on reducing nutrients, and some real progress, the bay foundation rates this at a dismal 15, after nearly two decades of effort.

Why? Scientists estimate we have increased nutrients a whopping seven-fold in the bay since pristine times. Even with the current targets, a 40 percent reduction by 2000, there will still be about four times pristine levels.

Larger reductions must be targeted, especially given growing populations of people, poultry and automobiles, all of which erode hard-won progress with nutrients.

Tweaking the technology at sewage treatment plants continues to promise more reductions; but in the bay's six-state watershed are sources of nutrients controlled poorly or not at all -- from agriculture, to septic tanks and runoff from city streets, to that gas-guzzling Lincoln Navigator you had to have instead of a Honda Civic.

Besides reducing sources of nutrients, we must also increase systems like wetlands and forests that soak them up before they reach the bay. We must also increase oysters, which filter the nutrient-fueled algae blooms that pollute bay waters.

About half of the bay tributaries and shorelines are "buffered" by forest, which gets a rating of 53. There are ambitious plans to increase these waterfront buffers and money to do it.

Oysters, the other potential big bay filter, are rated at 1 percent. But I found considerable optimism in talking to experts.

A lot of the optimism is based on good results Virginia is getting in experiments that grow oysters in reefs, as they grew naturally before centuries of dredging and tonging leveled them. Also, Maryland's oyster management is seen as improving and getting higher priority now.

To Goldsborough, oysters and shad "are two areas where we are poised to make fairly rapid progress."

Shad are rated at 2 percent. They should benefit from programs to breach dams that block their spawning rivers and from a phase-out of ocean fishing that takes them before they can enter bay rivers to spawn.

Crabs are rated at 50 percent. Scientists seem to be nearing consensus that crabs are overfished. Look for management to get more conservative. But crabs are so important, commercially and recreationally, we will always push them near the limit.

State of the Bay

Last week's column looked at why restoring the Chesapeake Bay is taking so long -- a new Chesapeake Bay Foundation report finds only slight progress since the early 1980s. Today's column looks at specifics among 12 areas of bay health used by the foundation to compile its State of the Bay report.

Pub Date: 10/16/98

Baltimore Sun Articles
Please note the green-lined linked article text has been applied commercially without any involvement from our newsroom editors, reporters or any other editorial staff.