Blueback herring swim in Lake Martin.
And that may be a problem.
Because like kudzu, fire ants and Chinese privet, blueback herring are not supposed to be here. It is currently considered an invasive species by the State of Alabama.
Blueback herring, also known as “river herring” and “summer herring,” as well as the scientific name Alosa aestivalis, is a common schooling fish native to North America’s Atlantic coast from Florida to Nova Scotia.
They are shaped like many members of the shad family and are silver with a greenish-blue back. These fish look very much like the threadfin shad found in Lake Martin, and in fact, both fish are members of the same family; however, blueback herring grow larger than threadfin shad, and they do not have the long “thread-like” projection off the back of their dorsal fins.
Bluebacks grow up to 16 inches long, though an average fish is about 10 inches long and weighs about a third of a pound.
They eat mostly plankton, but they also consume small insects, small fish and fish eggs, including the eggs produced by members of the bass family. They are known to have caused problems with largemouth populations in some lakes where they have been introduced.
These fish live up to eight years. Females become sexually mature at age 5 and can produce up 100,000 eggs.
These are fish that live in the ocean for much of their life but migrate up into freshwater rivers to spawn from March to the middle of May.
During spawning, the female Blueback Herring deposits her eggs on the bottom of fast-moving streams, where they stick to hard objects on the stream bottom. Young Blueback Herring hatch out in two to three days and remain in freshwater until they are three to seven months old, at which time they swim downriver to the sea if they are in their normal habitat.
In August, two men were charged with violating the Alabama invasive species laws after the discovery of blueback herring during a routine check of several commercial fishing boats in Lewis Smith Lake.
Michael L. Perry, 35, of Jasper, was charged with illegally importing and selling Blueback Herring. James M. Blanks, 58, of Crane Hill, was charged with two counts of illegal possession of the herring.
A following investigation revealed that Perry had been importing potentially thousands of blueback herring annually from Georgia.
Both men are commercial fishing guides who are accused of using Blueback Herring as bait for striped bass, and both face substantial fines and jail time associated with the violations, according to a press release from the Alabama Department of Conservation and Natural Resources (ADCNR).
Lake Martin is one of Alabama’s premier striped bass fisheries. It is suspected that striper fishermen brought Bluebacks to Lake Martin for use as striped bass bait.
The problem is that scientists are just now beginning to study the effect of Blueback Herring when they are introduced into a new lake.
According to the ADCNR, in recent years, blueback herring have become established in Lewis Smith Lake and threaten to disrupt the lake’s gamefish composition and feeding habits. Based on information from local anglers, state biologists think these fish were purposely introduced to augment the lake’s baitfish population.
Kevin Dodd, Law Enforcement Chief with the Alabama Department of Conservation and Natural Resources (ADCNR), said an explosion in the blueback herring population at the lake could create a ripple effect throughout the local communities in addition to the lake’s fishery.
“Given the existing economic impact of recreational fishing on Alabama’s lakes and waterways, it is no exaggeration to say that an invasive species like blueback herring could have a detrimental impact on local economies,” said Dodd. “These commercial fishing guides were playing with fire.”
The problem is that scientists just do not know whether the Blueback Herring could harm Lake Martin, as it has elsewhere.
“The competition that these fish pose to our native game fish is potentially substantial,” said Nick Nichols, ADCNR’s Fisheries Chief. “Invasive species can completely disrupt the balance necessary in the management of a quality fishery. The introduction of blueback herring into Smith Lake is a prime example of the negative impact that an invasive species can have on native ecosystems.”
Auburn professors Rusty Wright and Dennis DeVries directed a three-year project to determine the potential impacts of Blueback Herring on resident species in Smith Lake.
When contacted for an email interview by Lake, the scientists said, “At this point we cannot yet say whether they do or do not do any damage. Unfortunately they do have the potential to compete with our native fishes. In other reservoirs outside of Alabama where they have been introduced, some populations seem to have benefited while others have declined post-introduction. Those are the interactions that we continue to study.”
DeVries and Wright said the fish have been transported for use as striped bass bait in a number of lakes.
“Bluebacks have been stocked in other reservoirs as a supplemental forage for striped bass because they are relatively large, they have high caloric density (oily fish with a lot of forage value), they are an open water schooling fish, which is preferred prey type for striped bass, and they have similar temperature preference as striped bass, putting them in the same depth of water. As bait there really isn’t any evidence that they are superior to gizzard shad or perhaps large golden shiners.”
“In Lake Martin, we have no estimates of impact,” the two wrote in an email. “We simply know that they have been collected and therefore it is likely that there are at least small populations in both Lake Martin and Yates Reservoir. If populations increase, there is potential for Bluebacks to compete particularly with the juveniles of many of our resident fishes.”
DeVries and Wright said, “If anybody on Lake Martin sees Blueback Herring being sold for live bait or being illegally stocked (actually it is not legal for private individuals to stock any public waters with any species), they should report it immediately to the district ADCNR Fisheries Office.”