What is the history of sturgeon in the Delaware Bay and why are they endangered?

What is the history of sturgeon in the Delaware Bay and why are they endangered?

 Gregg W Rosner

sturgeon, delaware, bay, sussex county, kent county
Ernest Eiermen releasing a baby sturgeon in the Delaware Bay after a fish count in 2013

In the Delaware River before 1890, there were an estimated 180,000 adult females spawning, and now the total spawning adults in that river is believed to number fewer than 300.

Atlantic sturgeon are large, slow-growing, late-maturing, long-lived, estuary-dependent fish that live the majority of their lives in salt water, but hatch and spawn in freshwater. Historical catch records indicate that these fish were once abundant, supporting important colonial fisheries. In the late 19th century, demand grew for sturgeon caviar and the first major U.S. commercial fishery for them developed. This lasted from about 1870 until the 1950s with landings peaking in 1890. The commercial fishery collapsed in 1901 when landings were about 10 percent of the peak. Landings by fisheries targeting sturgeon declined to even less in subsequent years, with that trend persisting until moratoria on landings were established.

Small boat in the Delaware Bay pinging to keep sturgeons away from the blast area for the channel deepening project ... 2015
Small boat in the Delaware Bay pinging to keep sturgeons away from the blast area for the channel deepening project … 2015

While the historic range of Atlantic sturgeon included major estuary and river systems from Labrador to Florida, Atlantic sturgeon are now thought to be absent from at least 14 rivers they used historically, with spawning thought to occur in only 20 of 38 known historic spawning rivers.

The most significant threats to the species are unintended catch of Atlantic sturgeon in some fisheries; dams that block access to spawning areas, poor water quality, which harms development of sturgeon larvae and juveniles; dredging of historical spawning areas; and vessel strikes. As a result, NOAA Fisheries determined that listing sturgeon under the Endangered Species Act is warranted.


What is critical habitat and why a determination now? 

sturgeon map, delaware, new jersey, bay, atlantic ocean
Passive acoustic receiver locations (black dots) and example 8-
day satellite seascape classes from 21 May 2009 (aggregated from May
18 to May 25) in the Delaware Bay and coastal Delaware, Maryland,
and New Jersey.

Critical habitat is the specific areas within the geographic area, occupied by the species at the time it was listed, that contain the physical or biological features that are essential to the conservation of endangered and threatened species and that may need special management or protection. Critical habitat may also include areas that were not occupied by the species at the time of listing but are essential to its conservation. An area may be excluded from critical habitat designation based on economic impact, the impact on national security, or any other relevant impact, if we determine that the benefits of excluding it outweigh the benefits of including it, unless failure to designate the area as critical habitat may lead to extinction of the species. Critical habitat designations affect only Federal agency actions or federally funded or permitted activities. Critical habitat designations do not affect activities by private landowners if there is no Federal “nexus”—that is, no Federal funding or authorization. Federal agencies are required to avoid “destruction” or “adverse modification” of designated critical habitat. The ESA requires the designation of “critical habitat” for listed species when “prudent and determinable.” What provisions of the Endangered Species Act relate to critical habitat? To protect endangered and threatened species, the ESA makes unlawful a range of activities involving such species without a permit for purposes consistent with conservation goals of the ESA. These activities include take, import, export, and interstate or foreign commerce. “Take” includes kill, harm, harass, pursue, hunt, capture, or collect or to attempt to engage in any such conduct. The ESA requires Federal agencies to use their authorities to conserve endangered and threatened species and to consult with the NOAA  about actions that they carry out, fund, or authorize to ensure that they will not destroy or adversely modify critical habitat.

NRDC and Delaware Riverkeepers, successfully sued NOAA in 2015 to establish critical habitat for the Atlantic sturgeon. Critical habitat is the highest legal conservation and preservation of habitat from a federal agency. By establishing a CH for the sturgeon, other marine species attain a extra level of protection against federally funded projects. It may not prevent a beach replenishment loss of habitat, but will require extra caution by USACOE and DNREC etc.

What is the “hot” zip code for the sturgeon? 

sturgeon map occurence
Occurrence of Sturgeon

This UDel/DE State study below, just released to the public in Feb 2016, concludes that the coded red colors indicate the preferred sub-adult and adult habitat. Note that the area is subject to two known impacts; dredging of the DE Bay and the proposed ocean outfall for Rehoboth Beach into Hen and Chicken Shoals. (As the longshore current runs north into the mouth of the DE Bay, contaminants from the outfall will as NOAA has stated in their comments on the project, “Adversely affect” the essential fish habitat.)

Dynamic seascapes predict the marine occurrence of an endangered species: Atlantic Sturgeon Acipenser oxyrinchus oxyrinchus  

Matthew W. Breece1*, Dewayne A. Fox, Keith J.Dunton 3, Mike G. Frisk, Adrian Jordaan and

Matthew J.Oliver

What can be done to help?

In the next ninety-days your public comment in the Federal register can address concerns and support the effort. There will be further instructions and talking points for fisherman to solicit an important conservation measure which can help preserve fisheries in the future.

 Questions or Comments, send to the author …
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Gregg W Rosner

DE Surfrider Conservation Committee

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