Stock Assessments

[MakoMike]

The striped bass is in trouble again.

During the 1980s, wildlife managers said these big, full-bodied fish — favorites of anglers along the East Coast — were overfished. So they laid down severe catch limits. The population recovered, and fishing resumed in what is considered one of conservation's great success stories.

But now catches are down again, and some biologists say the problem may not be overfishing this time: It could be the weather.


EnlargeMaggie Starbard/NPR
Nearly 70 percent of the country's striped bass come to the Chesapeake Bay to lay their eggs, including inlets like this one, where the Choptank and Tred Avon rivers meet.
Brad Burns, who started fishing for striped bass in 1960, says he and his fellow anglers, Stripers Forever, are singing the blues about striped bass.

"What we hear from people that go striped bass fishing — the general trend very decidedly is down," Burns says.

Stripers live in the ocean as well as in estuaries and some rivers. Burns says members have been reporting fewer fish for the past five years. As for the cause?

"Well I don't know," he says, "and I don't know that anybody does."

A New Theory On Fish Levels

But Bob Wood thinks he might. Wood is a biologist with the National Oceanic and Atmospheric Administration. He studies his fish in a boxy little building on the Maryland shore of the Chesapeake Bay. In the semi-darkness, you can make out several vats with bubbling oxygen hoses. Each vat is home to striped bass or white perch, two species that spawn in the bay. This is where Wood's team studies the fish to figure out why striper numbers go up and down.

They thought they had the 1980s crash figured out: "The striped bass crashed because of overfishing," says Wood, "and then it recovered because we closed the fishery."

But now Wood has a new idea that's just taking shape. "This research, at first glance, seems to call that into question," he says.

This idea focuses not so much on fish but on the weather, and especially the Atlantic Multidecadal Oscillation, or the AMO. The AMO is a mashup of wind and ocean currents, a flip-flop that happens every 35 years or so in the North Atlantic.


EnlargeMaggie Starbard/NPR
Bob Wood (left) and Ed Martino are researchers at NOAA's Cooperative Oxford Laboratory in Oxford, Md. They think a weather pattern in the North Atlantic called the Atlantic Multidecadal Oscillation is responsible for wide swings in fish populations.
"Circulation changes in a way that warms the entire basin," Wood explains. "And you can imagine if you warm the entire North Atlantic basin, you're changing the weather because the air and circulation patterns above the ocean are affected."

Ed Martino, a fisheries scientist who works with Wood at NOAA, says when the AMO shift happens, it affects the local weather along the Atlantic Coast.

"You are talking about differences in temperature and precipitation, and therefore river flow or salinity, ultimately all affecting the base of the food chain," says Martino. "It's the way that the climate affects the microscopic plankton." Plankton are tiny plants and animals in the water, and that's what young stripers eat.

Understanding The Weather-Fish Relationship

Here's how Wood and his team think the AMO is messing with fish food. When it's in a warm phase, springtime along the East Coast actually tends to be wet and cool — more rain, more water, more food. In the years following that phase, striper numbers tend to go up. Then the AMO flips — drier springs, less rain, less food. After a lag, it looks like striper numbers start to decline.

More On The Chesapeake Bay

Shelling Out For A Chesapeake Bay Oyster Comeback
Efforts are being made to bring back the bivalve, for the sake of oyster lovers and the bay.
Manure, Fertilizer Part Of Chesapeake's Problem
Dec. 23, 2009
Researchers Get Dirty To Clean Up Chesapeake
Nov. 8, 2009
Wood says the past 100 years of fishing records show that very trend. And currently?

"It hasn't been so good in say the last five years," Wood says. "And it just so happens this is also the time when the Atlantic Multidecadal Oscillation seems to be switching phase."

Wood suspects it's switching into a "bad for stripers" phase, and he thinks it was also a down cycle that caused the striper crash in the 1980s. When that cycle ended, stripers recovered — not just owing to the fishing limits but because the weather bcame more favorable.

Janet Nye, who studies fish stocks for the Environmental Protection Agency, thinks this research could help fisheries managers.

"We would be able to say, 'OK, for the next 35 years or so we're pretty certain that the AMO is going to be more positive or warm,' and we would be able to say, 'These are the fish that respond favorably to that — you might be able to fish those more,' " she says.

Conversely, fish less in a down cycle, Wood says. "If we know that there is this cycle coming up," he says, "a trend that we are beginning to enter, we can keep that in our heads as we set limits."

If Wood's research is correct, it may take tougher catch limits to bring striper numbers back up again.

[piemma]

I have read a great deal about the Atlantic Multidecadal Oscillation. There definitely is something to it.
The facts remain that we are are on a downslide and a reduction in size and bag limit per day would not hurt.

[Mike P]

Originally Posted by piemma

I have read a great deal about the Atlantic Multidecadal Oscillation. There definitely is something to it.
The facts remain that we are are on a downslide and a reduction in size and bag limit per day would not hurt.

Yup---cyclical periods of scarcity have been noticed in the past, when fishing pressure on bass was a fraction of what it is now. Keep in mind that most of the bass clubs folded around the turn of the century (the 19th to 20th, that is) when bass became so scarce that members started dropping out.

[numbskull]

Blame it on the weather.
Good reason to go on killing 40% of the population each year.
And as long as we are careful to ignore the obvious and keep overestimating the population we can really kill even more.
Thank god for science.
Yup, it's the effing weather to blame yet again.

[numbskull]

On a more serious note, 4-6 years ago we had enough striped bass around to ensure great fishing for decades.

Where are they now. All offshore? Please.

The weather did not kill those fish.
Fishery management did.....with our help.

Blaming the weather for bad fishery management and fishermen's greed is a pathetic and destructive rationalization.

Weather did not kill the fish we had. We did (some much, much more than others).
If we had not killed those fish, weather would not be a big concern now.

[JohnR]

Originally Posted by numbskull

On a more serious note, 4-6 years ago we had enough striped bass around to ensure great fishing for decades.

Where are they now. All offshore? Please.

The weather did not kill those fish.
Fishery management did.....with our help.

Blaming the weather for bad fishery management and fishermen's greed is a pathetic and destructive rationalization.

Weather did not kill the fish we had. We did (some much, much more than others).
If we had not killed those fish, weather would not be a big concern now.

Maybe the weather would be a factor maybe it isn't - we really don't know. We DO know that increased rec pressure and increased commercial take contributed to what we are seeing. We do suspect that forage issues contribute to this. Hopefully the reg changes being bandied about for 2012 with a 40% reduction to the allowed mortality will become true and some more serious conservation can take place.

[numbskull]

Originally Posted by JohnR

Maybe the weather would be a factor maybe it isn't - we really don't know. .

Yes we do know.
That is my point.

The weather may have a lot to do with the failure of recent year classes, but the weather did not kill the fish we had.

WE, not the weather, are responsible for the current status of the stock.

WE, did it with the blessing of the fishery managers.

When breeding conditions are ideal, a small population can carry the stock.
When breeding conditions are poor, you need a large population to carry the stock, since spawning success is much lower.

We had a large population, now we don't. WE, with fishery management's blessing, killed those fish.

Blaming the weather for where we are now is a cop-out.

[Sea Dangles]

My next door neighbor has a house in Sandwich and loves to walk the canal.He starts at the boat basin and gets in his 4 or 5 miles on a regular basis. He tells me yesterday about the fishermen with six cows lined up behind them on the cell phone."Wake up Jr. please dear,and you come down too.I need three people here so I don't get arrested...."He says he gets asked all the time if he wants a fish by complete strangers just so they can kill more.A real thrill it must be!


Soon this talk of "Let's take back the Cup!" will be replaced by "I can't find the fish." The cameraderie that used to be known as Fishing Legs on this site apparently isn't enough without a Cup to hold in the air and pose for pics next to.The great causes which benefit sick children or fight cruel disease isn't enough either.

So the Bossman has the ball in his court and will disregard all the recent "favorable" stock assessments and wait for next year again to make a decision to pull the plug.Don't want to miss out on all the cameraderie. Age and wisdom seem to dictate common sense on this board.Some folks have never participated in the Cup,some have dropped out due to the writing on the wall.I have a sense they won't regret that decision.I will make the prediction that some day Bossman will regret his decision to lead his charges in search of a victory that will contribute to the defeat of the fish his site is named for.Tough choice.

[JohnR]

Originally Posted by Sea Dangles

My next door neighbor has a house in Sandwich and loves to walk the canal.He starts at the boat basin and gets in his 4 or 5 miles on a regular basis. He tells me yesterday about the fishermen with six cows lined up behind them on the cell phone."Wake up Jr. please dear,and you come down too.I need three people here so I don't get arrested...."He says he gets asked all the time if he wants a fish by complete strangers just so they can kill more.A real thrill it must be!


Soon this talk of "Let's take back the Cup!" will be replaced by "I can't find the fish." The cameraderie that used to be known as Fishing Legs on this site apparently isn't enough without a Cup to hold in the air and pose for pics next to.The great causes which benefit sick children or fight cruel disease isn't enough either.

So the Bossman has the ball in his court and will disregard all the recent "favorable" stock assessments and wait for next year again to make a decision to pull the plug.Don't want to miss out on all the cameraderie. Age and wisdom seem to dictate common sense on this board.Some folks have never participated in the Cup,some have dropped out due to the writing on the wall.I have a sense they won't regret that decision.I will make the prediction that some day Bossman will regret his decision to lead his charges in search of a victory that will contribute to the defeat of the fish his site is named for.Tough choice.

OK, I'll bite.

Funny. I don't recall seeing you at any fisheries meeting over the years. I don't recall seeing you calling for conservation until really late. And I don't recall you making any positive calls for reduction unless it has been to stir the pot.

Short version. Cup or no cup will have no real impact on the problem with the fisheries. As anglers we can continue to argue to make it a game fish or not, and stay divided. We can continue to blame it on the "Bossman" or the this group or that group. We can continue to point fingers at The Other Guy.

OR we can work together to reduce the pressure on the fish through the one single place that regulations are determined - good or bad - the fisheries management councils. I would have liked to see that process happen 2 years ago. It didn't. That process should happen this year in time to impact 2012 regulations. When those meetings happen, I hope to see you at a meeting Chris. (Really, I hope to see you there).

Ahhh, and while I would like to have more fun in the weeds, work beckons.

[Mike P]

Originally Posted by Sea Dangles

My next door neighbor has a house in Sandwich and loves to walk the canal.He starts at the boat basin and gets in his 4 or 5 miles on a regular basis. He tells me yesterday about the fishermen with six cows lined up behind them on the cell phone."Wake up Jr. please dear,and you come down too.I need three people here so I don't get arrested...."He says he gets asked all the time if he wants a fish by complete strangers just so they can kill more.A real thrill it must be!

I know a few guys who were taking two fish 40"+ on a morning tide, going home, changing their clothes just in case an EPO noticed them, and coming back for the afternoon tide to take 2 more. 80 lbs of fish a day, killed for ego alone.

Quite a few others took their two fish a day, every day of a run. Nothing illegal about it, but still--how much fish does any one person need? Some would spend most of the day on the phone trying to get their relatives, friends, and neighbors to take some of the fish off their hands.

How many times have all of us been in the position of releasing a decent sized fish, and have the guy next to us say something like, "hey, if you were going to put it back, why didn't you offer it to me first?".

Greed and ego cross the rec/comm border. The rec sector lives in a glass house if all they do is throw stones at the comms for the dwindling stocks. There's waste and greed all over.

All of the problems revert back to the management philosophy---"maximum sutainable yield". As George rightly points out, there's a 5 year lag between decreasing returns and effective steps to correct it. What "maximum sustainable yield" was in 2006 is different than what it is in 2011. But we're still using that F=.30 figure as the yardstick. If the stock assessments are correct, we have seen a 40% decrease in the stock biomass over the last 5 years. So we can't go on managing the stocks by allowing for killing 30% of them per year.