Wednesday, November 5, 2014

Northern loath or respect?

The northern snakehead (Channa argus) is one of many types of snakehead fish native to China, Russia, North Korea, and South Korea. Here in the United States, we consider the fish to be a highly invasive species.

So what does that mean for us? The snakehead is both feared and respected as "invasive" because: 1) it is not from around here; 2) has an ability to spread; and 3) believed to be causing damage to the environment and native fisheries.

As for snakehead they are destroying our native fisheries by eating every fish, insect and amphibian in sight, physically taking up space and aggressively defending areas, and they are reproducing like crazy and spreading very quickly.  Since the aquatic ecosystems around here didn't evolve with anything like this, the snakehead are like an NBA player in a pee wee basketball league...and they can really eat and get big! That just ain't fair!

Now they are throughout the Potomac and several other states:

So how do we stop 'em?
There is not much we can do other than keep them from spreading. Ensure no new introductions and try to knock them back as we find them. You can report sightings at the link above and until we find a better way we to try to kill em all.

Here the story, back in 2002 (only 13 years ago) a snakehead was found in a pond in Crofton, Maryland. They drained the pond and found (and killed) two adult and a bunch of babies. Someone later admitted they released two adults into the pond (sigh).  In 2004, multiple snakehead were found in the Potomac River and breeding was documented (sigh).

Snakehead can live outside water for several days and young can wiggle across land into new waters.

They are still a popular food item in Asia and much respected for their virtue as snakehead parents are known to sacrifice themselves to protect the babies.

They are listed as injurious wildlife under the Federal law making it a crime to transport them...

They like slow backwater areas and they put up a big fight...I hear they taste good. Be sure to kill if you catch em'

Shad fishing and our American cultural legacy

Over here in the Washington DC area, the shad run is coming up in April/May and I am already getting stoked.  Over here in the Potomac the American shad runs overlap with hickory shad.  Last year's run was intense, albeit brief, but man was that fun. 

The shad run over here is a very important part of history and shad fishing has been identified as very culturally important to many of our early native people and presidents.  

As Americans, they are part of our cultural identity!  George Washington loved to eat shad and honed shad fishing into a business and fed his workers and sold the fish in the market.  

Since then, the shad fisheries on East Coast have really taken a pounding from over fishing, water pollution, and hundreds of passage barriers.  They have to migrate to and from the ocean and face multiple challenges throughout. 

Through hatchery programs and catch and release fishing, they are slowly recovering from near rock bottom. 

Did you know that shad are actually a type of herring? Shad have also evolved an ability to detect ultrasound. This ability is thought to help them avoid dolphins that find prey using echolocation.
Here are some more fun facts about American Shad: 
        A.K.A. “common”, “white”, “Atlantic” shad
        Large shoulder spot may be followed by 4-6 fainter spots
        Lower jaw doesn’t extend much more than upper jaw
        Historically recognized regional food fish with high commercial value
        Current world record 11 pounds, 4 ounces
        Average 20-24 inches (up to 30), the largest of all the shads
        Schooling and highly migratory (anadromous)
        Spend 3 to 6 years in the ocean before migrating upstream
        Feed primarily on plankton, but also small crustaceans and small fish and eggs
        Females spawn around age 5 or 6, males at age 4 or 5
        Spawning occurs after sundown in gently sloping gravel or sandy bottom areas
        Females broadcast batches of around 30k eggs into the water, males then fertilize
        Each female can produce up to 600k eggs
        Eggs are semi-buoyant and carried downstream with the current, hatch in 7-10 days
        Start spawning once water temperatures have reached 55-68 degrees Fahrenheit
        Can survive and make several spawning runs per lifetime (around 22-45% in the Potomac are repeat)
        Feeding instinct triggered by factors such as water turbidity and temperature
        Male fish are feisty jumpers and put up a good fight, female (roe) not as much
        Generally stay fairly deep in the water column near the bottom unless water is high
        Generally fished for with shad darts, and small spoons and spinners
        They taste great, generally low in accumulated toxins, and very high in omega 3 but over here are catch and release only!

Here are some neat facts about Hickory Shad:
        A.K.A. “hickory jacks” or “tailor” shad
        Smaller cousins to the American shad in the herring family
        Current world record 2 pounds, 14 ounces
        Average 12-20 inches
        Bluish-silver on the sides with a gray-green back
        Dusky shoulder spot may be followed by several faint spots
        Lower jaw extends much further than upper jaw
        Females are larger than males
        Low commercial value, but a popular sport fish
        Feed primarily on small fish, but also will eat small squid and crustaceans
        Schooling and highly migratory (anadromous)
        Spawning run usually precedes that of American shad
        Spawning occurs in a diversity of physical habitats ranging from backwaters to sloughs
        Can survive and make several spawning runs per lifetime (around 30-60% here in the Potomac are repeat)
        Females spawn between age 3 to 9, males at age 2 to 7
        Hickory shad don’t really feed during the spawning run
        It is believed that they hit the lures in aggressive spawning defense
        Generally fished for with shad darts, and small spoons and spinners
        In the Potomac, they are catch and release only!