The Delaware River is one of the most valuable natural resources in the northeast. Not only is it a lifeline that supplies clean water for millions, an important transportation source in its lower regions and a principle part of our history, it also provides all types of recreation for the millions who live within its bounds.
Growing up in the Delaware Valley, I’ve see the river from its depths of pollution in the 1950s and ‘60s to its resurgence to a clean viable habitat of the last 25 years. However, once again, the river is seeing several major threats to the health of its inhabitants. So here is a look at the four threats to nation’s mother river on whose shores our nation was born.
The four threats to the river that we are speaking about are the Columnaris virus, that so far has ravaged the smallmouth population and could spread to other fish, the appearance of the didymo moss (didymosphenia) that has been recently found in the upper river from the Gap north and will more than likely spread down river, the snakehead fish that are spreading out in the tidal river and could move into the non-tidal river and the flathead catfish which are also increasing in the river.
• The Columnaris virus is the same plague that hammered the smallmouth in the Susquehanna River about 10 years ago. The virus is a secondary virus that is similar to AIDS in that it needs a triggering factor for it to cause problems. The virus is present in fish, as well as soil, and under normal circumstances remains dormant until an external factor activates it. Fish that contract the disease die with in a matter of days, and the disease preys on the weaker fish such as yearlings. Fish in the first stages of the virus have sores on their bodies, mucous in their gills and problems with their fins.
There is no cure for the disease, and it is not harmful to humans. Other than letting the disease run its course, the only way of combating it is to find the external factor that triggered the outbreak and eliminating it. These factors can be some type of pollutant, a chemical change in the water and a multitude of other environmental factors. The triggering factor for the virus in the Susquehanna was never identified, and the river is only now seeing its smallmouth population bounce back.
• Didymo is an invasive species of moss (also know as rock snot) is common to waters farther north. However, in recent years, it has been slowly spreading farther south into warmer waters. Its microscopic spores can latch on to anything and be transmitted to other waters without even being seen. While the spores can latch on to birds and animals, scientist attribute man as being the biggest spreader of the spores. Scientific evidence shows that felt-soled boots, clothing, the bottoms of boats, live wells, bilges and trailers have been the cause for introduction of the moss into many streams. The moss can get so thick that, in extreme cases, it can cut off oxygen and sun light to a stream, thus hurting bug hatches and harming the food chain.
Mike Stocker/Sun SentinelIn Florida, Corey Nowakowski holds two of the 33 Bullseye Snakehead fish he caught to win an April tournament. The fish has teeth, lungs and a nasty disposition. It can walk over land, and it eats bass, turtles and even iguanas. It's also an invasive species, prompting anglers to organize tournaments to catch the illegal fish -- which also happen to be quite tasty.
Some states have outlawed the use of felt-soled boots; however, the alternatives are very expensive. It would take too much space to go into the pros and cons of felt soles and their alternatives; however, it will suffice to say wading safety is also a big concern. Disinfecting the hull of your boat, bilges and live wells is another way of containing the moss; however, enforcement is extremely difficult. Since the moss is spread by spores in the water, it will suffice to say that the moss will eventually spread down river.
• Snakeheads are native to Asia and Africa and were brought to America as pets kept in aquariums and were eventually released in U.S. waters. They are voracious feeders and prolific spawners which can grow to lengths of 2-3 feet and are a threat to all native species. The snakehead can live out of water for several days and can even move across wet land up to a ¼-mile. It breathes with a suprabranchial organ (a type of primitive lung).
A single female can release up to 15,000 eggs at once. So far the snakeheads have been found in the lower tidal river. They are sometimes misidentified, because they are similar to the bowfin which is a native inhabitant of the Delaware. The New Jersey Division of Wildlife advises any angler catching a snakehead to kill the fish and not release back into the river.
The flathead catfish are native to waters west of the Appalachian Mountains. They can grow to lengths of 60 inches, reach weights of 120 pounds and live for up to 20 years. They are voracious feeders that feed on just about anything that will fit in their mouth.
An average female can produce 2,640 eggs. They are already wide spread in the Susquehanna River system. They were first caught in the Delaware in Lambertville in 2009. The Division also advises anglers not to release any flatheads that are caught back into the water.
The Delaware, over the years, has survived many threats, and it will be interesting to see how the river fairs as these threats develop. Hopefully she will survive these new threats.
Posted Mon May 28, 2012 9:47 am