Fish need oxyen too

Chris Deacutis, PhD and chief scientist for the Narragansett Bay Estuary Program with a Seabird oxygen-temperature-salinity sampler. Chris has been working on the issue of excess nutrients (nitrogen) and low oxygen in the upper half of Narragansett Bay for ten years.

Bob Anderson of East Providence and his son-in-law Ben Vosper of Tucson, AZ with the keeper fluke they caught while fishing under the Newport Bridge.

Jeremy (left) and Paul Stedman (right) of Worcester County with the bluefish they caught after fluke fishing near the Newport Bridge last week.

Fish need oxygen too

“I need to breath. Quick... find me some oxygen” said the Greenwich Bay summer flounder to the striped bass. “Hurry… follow me to the deep hole off Warwick Neck where there’s plenty of oxygen to breathe” said the bass. Fish may not communicate like this but they certainly position themselves in places where there is food and oxygen.
Chris Deacutis, PhD and chief scientist for the Narragansett Bay Estuary Program (NBEP) at the URI Bay Campus has been working on the issue of excess nutrients (nitrogen) and the low oxygen issue in the upper half of Narragansett Bay for over ten years. Chris said, “Years ago the Providence River, the Seekonk River and the Bay were in bad shape. (History relates) the rivers were filled with dead animals, industrial waste and other pollutants. It smelled so bad people would faint from the smell.”
Today things are better but Bay advocates are still combating nutrients in the Bay that create algae blooms (which actually create oxygen). But as algae decays it uses oxygen and reduces the oxygen level in the water, often times well below the levels that fish need. This low oxygen level has occurred in Greenwich Bay in the summer as well as in other parts of the Bay.
With a prevailing southwest summer wind in Narragansett Bay, Greenwich Bay (particularly East Greenwich Cove), does not get flushed and low oxygen levels are more prominent there according to the NBEP which measures oxygen levels in the Bay. In fact, “The famous menhaden fish kill of August 2003 was clearly caused by a sever hypoxia (actually anoxic – no oxygen) events that centered on western Greenwich Bay”, said Chris Deacutis.
The NBEP eliminated the East Passage, the Mt. Hope Bay and the lower Bay from measurement because oxygen levels in these areas are good. The channel in the east passage acts as a conduit for flushing and mixing. Oxygen levels in deep water off Warwick Neck mix well too due to the water passing from the east to the west passage and back. Water at Quonset Point and south have good oxygen levels too.
The NBEP blog states that “Marine animals breathe oxygen too and when oxygen levels drop below 3mg/L there is not enough oxygen to go around. Creatures that live on the bottom of the bay such as oysters, littlenecks, and marine worms are at a greater risk during hypoxic events because they cannot move to a different area. Schooling fish such as menhaden are also affected by hypoxia because they are often chased into coves by predators such as striped bass and the school will use up the oxygen faster than it can be produced by photosynthesis or mixed into the water at the surface from the air.”
Dr. Deacutis said, “Early on, sewerage treatment plants did a good job of taking solids out of the waste but nutrients have just started to be addressed in the Bay by treatment plants in the past five years." Plants that have been treating for nutrients include Warwick, Cranston, East Greenwich and the Narraganesett Bay Commission. The Field’s Point plant plans to start treating nutrients in 2013 said Deacutis.
What does this mean for fish and anglers in the Bay
So I asked Dr. Deacutis what low oxygen levels and poor mixing means for recreational and commercial fishing in the Bay. Fisherman should advocate for and support programs that aim to clean water and lower nutrient levels. Anglers should also support efforts to plant sea grass as the grass acts as a haven for small marine creatures and bait that large fish feed on.
Oxygen levels in upper, mid and low water levels seem to explain a few things about fishing in the Bay. Fishing at Warwick Neck has been always been good; this could be due to the water moving, tossing around bait as well as the oxygen levels mixing well throughout the water column including the bottom of the water column where large fluke have been taken in recent years. Fishing in the East passage is also good… due to bait fish and menhaden runs up the East Passage to the Providence River in the spring, but one has to wonder if the flushing and mixing that provides better oxygen supply and mixing in the water column is also contributing to better fishing.
Greenwich Bay fishing is good in the spring with great school striped bass fishing and blue fishing throughout the summer months. Fishing here slows down in the summer but bluefish tend to feed at the top of the water column and are not as affected as much by low oxygen levels. For more information visit the NBEP website at www.nbep.org and an associated blog at http://nbep.wordpress.com/ . Brown University hosts the dissolved oxygen (DO) website (called Insomniacs) which has oxygen level maps of various Bay areas. For this website visit http://www.geo.brown.edu/georesearch/insomniacs/index.html .

RISAA members receive “Making a difference” award
Two local sport fishing advocates, Stephen Medeiros, president and executive director of the Rhode Island Saltwater Anglers Association (RISAA) and RISAA member Capt. Alan Anderson were among the five winners of Sport Fishing Magazine's "Making A Difference Awards." The winners were announced on Wednesday. The awards are given to "individuals who have made a positive difference in saltwater recreational fishing."

NOAA announces new aquaculture program
NOAA announced the Aquaculture Technology Transfer Initiative last week which will foster public-private partnerships on regional projects that showcase innovative sustainable practices, jump start private sector investments, and create employment opportunities in coastal communities.
NOAA Administrator Dr. Jane Lubchenco said, “Aquaculture is a critical component to meeting increasing global demand for seafood… this initiative provides an opportunity….”

Where’s the bite
Bluefin tuna fishing is good. Jay Fissette of Coventry said, “We were on our way home, just south of the Fairway buoy when one of our lines went off and we boated our first bluefin of the season.” Many captains say bluefin have been more plentiful in the past five years. Last week, NPR reported scientists now believe bluefin are spawning somewhere other than the Gulf of Mexico. The fish move quickly, a fish tagged on the east coast of the US traveled to Europe in just 53 days.
Last week NOAA announced the United States joined more than 50 countries in a recommendation to regional fishery management organizations (Ramos) to better track vessels engaged in illegal, unreported and unregulated (YOU) fishing for tuna and other highly migratory species.
Striped bass fishing is good off Block Island and coastal southern shores. Bay fishing has slowed dramatically. Last week Governor Chaffee signed a striped bass bill calling for stiffer penalties on those taking striped bass illegally. RISAA successful advocated for the bill.
Fluke fishing is very good with anglers catching keeper fluke around Newport and Jamestown south of the bridges. Bob Anderson and his son-in-law Ben Vosper caught keeper fluke just south of the Newport Bridge alongside Rose Island last Thursday aboard No Fluke Charters. Anglers filing fishing reports on the RISAA blog report a good fluke bite with shorts mixed in. Francis Fleet vessels and the Seven B’s party boats report a good fluke bite last week. Fish in the seven to eight pound range were caught Saturday on the Seven B’s with the largest fish weighing nine pounds.
Bluefish are plentiful off coastal waters and in lower Narragansett Bay. Jeremy Anderson and his dad Bob caught bluefish just over eight pounds near the Newport Bridge after fluke fishing. Good sized blue fish were caught Friday by Darrell Hattern of North Kingstown and Mike Swain of Coventry while fishing with live menhaden at Bear Point, Prudence Island. Mike Swain said, “We would snag a menhaden and before we could work it to the boat the bluefish would bite it in half.”