The Society for Ocean Sciences Blog

2010-10-29T05:18:00.001-07:00

Eat a Ray - Save the Bay?

Let's Wait Just a Minute

Those who ignore history are bound to repeat it.

By Dr. Drew Ferrier

The Chesapeake Bay has its problems, but one of them is not the lack of Atlantic cownose rays. Rays spend the summer months in the Bay and can be seen frequently feeding in the shallows or swimming near the water's surface from the Choptank River to the mouth of the Chesapeake Bay. There are likely 100's of thousands - perhaps millions - of them. Many people consider them a nuisance: a major predator on commercially important shellfish; an important destroyer of sea grass beds; or a common hidden threat ready to inflict a painful sting on unsuspecting human waders. Is this all true? Are rays detrimental to the Bay? Must we control their numbers?

Do we have all the information we need to answer these questions or are we working largely from anecdotal findings?

In the minds of many Bay stakeholders rays are bad news. They feel that their numbers need controlled, and perhaps they can turn a profit at the same time. Some commercial fishers have adopted the slogan "Eat a Ray - Save the Bay". It is too soon to know whether a commercial fishery for Atlantic cownose rays can be established either regionally or perhaps internationally. However, the time is ripe for us to begin to understand more about the biology and ecology of these animals in the Bay. We believe that comprehensive empirical evidence is lacking to support many ideas about the role and impact of rays in the Bay. However, even in the absence of data, assumptions about the negative impacts of rays continue to be made.

The prudent approach to this issue is to learn more about the role of cownose rays in the Bay so that we can make measured judgments about the significance of their impacts and the degree to which their population may need to be controlled. The history of Bay fisheries is littered with declining and over-harvested species that have received little attention until their populations were in dire straits: Atlantic sturgeon, oysters, shad, and river herring to name a few. We are currently spending a lot of time and effort to restore these populations. Why not take a proactive approach to nascent fisheries as commercial fisheries search for the next exploitable "crop" from the Bay?

At the most recent conference of the American Elasmobranch Society in July, a resolution was passed that "urges Atlantic states where cownose rays are being landed, particularly Virginia and Maryland, to immediately impose precautionary cownose ray catch limits and initiate development of a population assessment and science-based interstate management plan, as a matter of priority." The Society for Ocean Sciences strongly endorses this resolution. Let's learn from past management mistakes.

Earth Day

2008-04-27T04:18:00.000-07:00

This past Earth Day, Drew and I brought along our mobile touch tank to Quiet Waters Park in Annapolis, Maryland. It was a fabulous day and luckily the rain held off for us!

Our exhibit featured a tank with fiddler crabs, whelks (a gastropod mollusk), sand dollars and spider crabs. We also had various artifacts on display and a microscope set up to view zooplankton (small marine organisms like sea monkeys) and baby whelks. Many of the organisms and artifacts on display were found along the beaches of the Chesapeake Bay.

One of the specimens that attracted a lot of attention was our fossilized oyster shell from the Bay. People were amazed at the size of this thing – probably 3 times the size of oysters that go to market today. People were curious as to why they don’t get that big anymore – there was no simple answer to that question. There are many reasons why: environmental degradation; oyster diseases; and over-harvesting all play a role.

It was so much fun to have people recognize the specimens, then show such surprise when I told them what it was! So many people were surprised to learn that the “black bug looking thing” was a skate egg case washed up on the shore. Or the “yellow rattle thing” was a whelk egg case.

The kids were fantastic and asked questions that some college kids don’t even think about. When is the curiosity lost in people? I guess being curious just isn’t cool. I want to change that. How will people learn about environmental issues without that first sense of wonder?

The Plastic Sea

2008-03-28T10:58:00.000-07:00

I always knew that marine debris was a problem, plastics in particular, but I never realized how big a deal it was. It seems that everything I am about to share with you was brushed under the carpet with little or no media attention. It doesn’t really occur to people (myself included until today!) that plastic debris can be anything from plastic resin pellets (the raw material used in the manufacture of molded plastic) to rubber duckies.

Plastic resin pellets are accidentally spilled into the ocean, via sea transportation from the east to the west as well as during the land manufacturing process. It is still unclear how these pellets affect marine organisms. However, the accidental ingestion of the pellets by marine animals is well documented. A group of Japanese scientists have shown that some pellets absorb pollutants from the ocean, which upon ingestion accumulate in the tissues of the organism. Unfortunately, some sea birds mistake the pellets for food. In addition, researchers such as Gregory and Carpenter have shown that the pellets contain PCBs.

After reading about this situation I was appalled. I immediately wanted to know what was being done to solve the problem. The International Convention for the Prevention of Pollution From Ships was introduced with the intention of banning the dumping of most garbage and all plastic materials from ships at sea. It seemed to be a success, with a total of 122 countries having ratified the treaty since then. However, in June 2006, the United Nations environmental program report estimated that there is an average of 46,000 pieces of plastic debris floating on or near the surface of every square mile of the ocean. Evidently, even with treaties in action a lot still needs to be done.

The situation was also discovered by Captain Charles Moore, of the Alguita’s. He and his crew witnessed what they called “the Exxon Valdez of plastic bags” while carrying out a research cruise. While crossing the North Pacific Gyre, the crew discovered a 10-mile-wide mass of plastic bags floating in the ocean. An estimated 6 million bags were destined for Taco Bell restaurants throughout the US. These eternal jelly-fish mimics were found floating more than 1,000 miles west of their destination.

Some of these plastic bags are freed from their captivity of the swirling gyre and drift onto the North Pacific shore. However, many of the bags are trapped by calm winds and the gentle currents of the North Pacific's gyre, baiting marine organisms to feast upon their bounty for years to come. The next time you are walking along a beach, look for one of the thousands of bags that wash up daily from countless spills.

There are things we can all do in our daily lives to help prevent plastics from entering our seas. The most obvious one is to not litter! We all should make the effort to take our used plastic bags to supermarkets where they can be recycled. I myself will confess, my diligence is not absolute on this matter.

Another way we can prevent the spread of plastics and one that has become quite a pet peeve of mine, are people releasing balloons. Balloons seem so harmless. After all, they are decorations for birthday parties and are associated with children’s laughter, how can they create such havoc in the marine environment? The pretty floating balloons drift up and eventually back down, their destination – a marine environment. When a deflated balloon lands in the sea, it looks like an appetizing jelly-fish to many marine organisms. Countless sea turtles are killed each year due to the accidental ingestion of balloons.