Updates on the Northern Snakehead Fish in Maryland
by Eric Schwaab, Director,
Maryland DNR Fisheries Service
We are preparing to move forward to control the population of northern snakeheads in a small Crofton pond. While we take this situation very seriously and believe that it merits swift and decisive action, the media attention in recent weeks focused on the issue has been nothing short of amazing. The positive coming from it all has been a poignant reminder that we all share a responsibility to take great care in what we purposefully or accidentally release into our natural systems.
Regarding the problem at hand, a panel of scientific experts recommended treatment of the pond first with herbicide to eliminate the existing thick vegetation, then follow that with application of a commonly use fish toxin. The plant life will recover quickly, and steps will be taken to restore native fish life after we are confident that snakehead fish have been eradicated. Secretary Fox accepted the panel's recommendation and we expect to initiate implementation very soon.
As we move through snakehead response, we set our sights on other pressing business at hand. Among those issues is Amendment 6 to the Atlantic coastal striped bass management plan. We soon anticipate the release of the public draft of the amendment, which will be subject to public hearings up and down the coast in September. Amendment 6, to be developed and adopted by the Atlantic States Marine Fisheries Commission, will govern management of the Atlantic coast population striped bass and establish standards for each state to meet in its management program. All interested fishermen are encouraged to participate in review and comment of this important document. Watch our web site for updates and meeting locations.
The northern snakehead is all anyone wants
to talk about. For those unaware, the snakehead is a top-level predator fish
native to China. In late June we received a picture from an alert angler, Paul DiMauro who caught the unusual fish in a small pond in Crofton. Since those
initial reports, additional reports of encounters, and one catch by another
angler, Joe Gillespie of Crofton, confirmed the presence of more than one northern
snakehead in the pond.
Since that time, we have worked to assess the scope of the
problem and the threat posed by this non-native fish, considered various options
for eradication of the fish from the pond, and generally worked with the media
to separate fact from the growing fiction surrounding the fish. In the end,
our goal will be to eliminate the threat to our native fish populations and
use the attention brought to bear by this event to remind people of the dangers
associated with careless introductions of non-native species into our waterways.
Like many other non-native species, the snakehead has the
potential to disturb functioning natural ecosystems. As a top-level predator
it can quickly impact local fish populations through predation or displacement.
While many non-native species can spread rapidly, impacting an ever-broadening
area (think of zebra mussels, gypsy moths and mute swans to name a few) the
snakehead's ability to spread is limited by its mobility and habitat requirements.
Although it has been reported as a walking fish, the real threat is its ability
to live for days out of water and potentially wallow its way to other water
bodies, or be spread by human intervention or flood. While there is a concern
that it could spread to the nearby Patuxent River system, there is no evidence
that such spread has occurred. Additionally, the species is not tolerant of
salinity, so it is unlikely to threaten broad areas of the Chesapeake Bay region.
As for control, our ultimate goal is eradication as expediently
as possible. To accomplish that result with certainty requires careful consideration
of various options. Given the thick vegetation in the pond and the biology of
the snakehead, immediate options are limited. Traditional electro-shocking techniques
and large scale netting operations would have to wait for the vegetation to
clear. Other even more aggressive techniques like poison, or even draining the
pond, can not achieve the desired results with certainty at this point, and
if not done correctly could lead to other undesirable consequences or increase
the threat of spread of the fish.
At this point our intention is to conduct a thorough threat
analysis, continue assessment and monitoring of the population of snakeheads
in the pond, and evaluate various eradication options to be employed both now
and later this year when vegetation clears naturally from the pond. We have
also requested assistance form local fishermen, asking them to retain and kill
any snakeheads they catch, and notify us as soon as possible.
Perhaps most importantly, this situation again points out
the responsibility we all share to refrain from purposeful release of fish to
our waterways and to take great care to prevent even accidental introductions
of non-native bait, plants or other species when we go fishing. The northern
snakehead is only the most recent example of a long list of species of concern.
Thanks for your help and support.
580 Taylor Ave, Annapolis MD 21401