NOAA Teacher at Sea: Bruce Taterka
NOAA Ship: Oregon II
Mission: SEAMAP Summer Groundfish Survey
Geographical Area of Cruise: Gulf of Mexico
Date: Tuesday, July 13, 2010
It’s All Connected
Weather Data from the Bridge
Time: 0015 (12:15 am)
Position: Latitude = 28.13.24 N; Longitude = 094.15.51 W
Present Weather: Cloud cover 20%
Visibility: 6-8 nautical miles
Wind Speed: 20 knots
Wave Height: 2-4 feet
Sea Water Temp: 29.4 C
Air Temperature: Dry bulb = 29.6 C; Wet bulb = 25.7 C
Barometric Pressure: 1011.96 mb
I’m seeing it now in the Gulf of Mexico. Obviously, the ocean environment is connected to human activities – the BP-Deepwater Horizon oil spill makes that abundantly clear. But there are also countless natural connections, and much less obvious human impacts, that must be understood and assessed if the Gulf ecosystem is to be protected. Commercial fish and shrimp stocks can only be sustained through a careful understanding of the human impact and natural connections in the Gulf.
That’s why we identify and count every organism we bring up in a trawl. Sometimes we get 50 or more different species in one catch, and we don’t just count the commercially important ones like red snapper and shrimp. We count the catfish, eel, starfish, sea squirts, hermit crabs and even jellyfish we haul in. Why? Because even though these organisms might seem “unimportant” to us, they might be important to the red snapper and shrimp. They also might be important to the organisms the red snapper and shrimp depend on. And even if they’re not directly important, studying them might tell us important things about the health of the Gulf.
I’m learning a lot about this from the incredibly knowledgeable marine biologists in the science party. Brittany Palm is a Research Fishery Biologist from NOAA’s Southeast Fishery Science Center (SEFSC) in Pascagoula, MS, and leader of the day watch on this leg of the Oregon II’s Summer Groundfish Survey. Brittany is working on her M.S. on a fish called croaker, Micropogonias undulatus, studying its stomach contents to better understand its position in the food web. Croaker is not an economically important species, but it lives in the same shallow sea floor habitat as shrimp so shrimpers end up hauling in a huge amount of croaker as bycatch. So, when the shrimping industry declined in 2003-2004, the croaker population exploded. Since croaker are closely associated with shrimp habitat and the shrimp fishery, we might gain important insights by studying croaker population and understanding what they eat, and what eats them.
Alonzo Hamilton is another NOAA Fishery Biologist from the SEFSC. Alonzo explained to me that there’s a lot to be learned by looking at the whole ecosystem, not just the 23 commercial species that are managed in the Gulf. For example, many of the crabs we commonly catch in our trawls are in the genus Portunas, known as “swimming crabs.” Portunas species normally live on the sea floor, but when severe hypoxia sets in, Portunas crabs can be found at the surface, trying to escape the sever oxygen depletion that typically takes place at the bottom of the water column.
Biologist from NOAA’s Northeast Fishery Science Center in Woods Hole, Massachusetts. He’s working on the Oregon IIright now to support the SEFSC because of huge manpower effort demanded by the oil spill. Sean explained that the NEFSC has been conducting its groundfish survey annually since 1963, making it the longest-running study of its kind. Originally the survey only looked at groundfish population, but as our understanding of ecosystem dynamics increased over time, more and more factors were analyzed. Now NEFSC looks at sex, age, stomach contents and many other species besides groundfish to obtain a more complete picture of the food web and the abiotic factors that affect groundfish. NEFSC even measures primary production in the marine ecosystem as one tool to estimate the potential biomass of groundfish and other species at higher trophic levels.
Andre DeBose is a NOAA Fishery Biologist from the SEFSC and the Field Party Chief for the Summer Groundfish Survey. In addition to leading the science team on the Oregon II, Andre is conducting research on Rough Scad, Trachurus lathami, an important food species for red snapper and important bait fish for red snapper fisherman. By gaining a better understanding of the relationship between Red Snapper and its prey we can better understand, and better manage, the ecosystem as a whole.
There’s a lot of information to be learned beyond just counting fish. By taking a wide look at the marine environment we can better understand how the whole ecosystem functions. This enables us not only to be more informed in setting sustainable catch levels, but also enables us to identify and respond to things that contribute to hypoxia and other problems that degrade habitat and reduce populations. It’s all connected.