American Birding Podcast



ICYMI: Open Mic: The Question of East Coast Pelagic Boundaries

Open Mic: Nate Dias


    When birders and state Bird Records Committees speak of a “state list” or a “first state record” – they are referring to bird species that have
been recorded within a state’s official legal boundaries, as determined by U.S. law and court decisions.  Whether on land or at sea, the legal borders of a state (or county or city) and its waters  *must*  be used in determining where a bird record is assigned.  Otherwise it’s not truly a “state list” in any real / official capacity.

There has been considerable discussion (and controversy) in recent years about state pelagic birding borders.  The American Birding
Association, eBird, and some state Bird Records Committees recognize what is known as the “closest point of land rule”.  This means that an offshore bird record from a given location / set of coordinates lies within the borders of the state that controls the closest point of land to those coordinates.  In U.S. law and international law, this is known as “the principle of equidistance” – i.e. offshore borders consist of a series of points that are equidistant from the closest points of land in the two neighboring states, nations, etc.

Other state Bird Records Committees recognize different borders – some consisting of east-west lines extended from their coastal land borders, others consisting of a variety of formulas.  Unfortunately, this second group of Bird Records Committees are in error by not following their respective states’ legal/official offshore borders.  Though most birders do not know it: U.S. law, U.S. courts, and U.S. federal agencies use the principle of equidistance (AKA closest point of land) to determine offshore state boundaries.  The U.S. Supreme Court has issued repeated opinions that this principle is to be used to determine offshore state boundaries (both in state waters and federal waters).



Pelagic Boundaries as determined by closest point of land.

Background:  according to U.S. law, states only control waters between 0 and 3 miles from shore.  These are known as “State Submerged Lands” and are commonly referred to as “state waters” – they were reaffirmed in the Submerged Lands Act of 1953.  The exceptions are
Texas and the west coast of Florida, where State jurisdiction extends from the coastline to 10.066 miles into the Gulf of Mexico.  An offshore  border / boundary between state waters (0-3 miles from shore) is known as a “lateral seaward boundary“.

Waters in the 200-mile US Exclusive Economic Zone lying seaward of state coastal waters are under U.S. federal jurisdiction – as reaffirmed in the Outer Continental Shelf Lands Act.  While resources from these 3-200 mile offshore waters are still assigned to states (examples:  oil & gas royalty revenue, fisheries revenue, wind energy fees and royalties, shipwrecks, reefs, etc.), the federal government has jurisdiction there and has decision-making authority on boundaries between states.  These federally-determined offshore state boundaries from 3-200 miles are known as
Offshore Administrative Boundaries“.

Trindade TJ

Herald (Trindade) Petrel, photo by Tom Johnson, used with permission. A state first, but for GA or SC?

Another term used in discussions of offshore boundaries is “baseline” – that means the officially-recognized coastline (which can shift over the years, particularly around river mouths and inlets).  The U.S. Government periodically updates the baseline for the entire U.S. coast (to
reflect changes to the coastline and to offshore islands).

Due to disputes among the states over offshore boundaries in federal waters: the federal Minerals Management Service, National Ocean Service, and State Department developed an updated nationwide baseline and applied the ‘principle of equidistance’ to it to produce an updated set of offshore boundaries seaward of the Submerged Lands Act’s state waters (3-200 miles offshore).  These updated offshore state boundaries, their methodology, and helpful background information (including maps) were published in the Federal Register in 2006:

* From the site linked, note this paragraph especially:

“The U.S. Baseline Committee has firmly established equidistance as the principle for domestic and international boundaries. The President formed the Committee in 1970 to resolve Federal baseline points from which to establish various jurisdictional and boundary issues, such as Federal/State boundary points and the extent of the territorial sea. The Committee has directed the  Department of the Interior and all other agencies to apply this standard in dealings with coastal states and for international purposes.”

In terms of state waters (0-3 miles from shore):

Boundaries between state offshore waters (AKA lateral seaward boundaries) have been litigated many times.  Texas v. Louisiana (1976) was a
noteworthy case argued before the U.S. Supreme Court, as was Georgia v. South Carolina (1990).  In both cases (and others), the Supreme Court upheld the principle of equidistance for determining the lateral seaward boundary (border between state waters).   It should be noted that these two specific decisions only dealt with the lateral seaward boundary – i.e. the localized area around those states’ borders, out to the limit of state waters.

The following web application from NOAA is a neat tool for displaying states’ offshore boundaries (in both state and federal waters):

In addition to offshore borders, it can show all kinds of GIS layers overlaid on a marine map surrounding North America.  To see the
individual GIS layer checkboxes, you have to hit the little “+” buttons to expand the categories and reveal the checkboxes.  Note: the NOAA application requires Adobe Flash player.



A state-first Fea’s Petrel seen at the Charleston Bump, but for SC or GA? photo by Nate Dias


You can display all the LEGAL + OFFICIAL state offshore borders by selecting 1) the Submerged Lands Act Boundaries, 2) the 200 nm EEZ boundary, 3) the Federal OCS Administrative boundaries and 4) the lateral seaward boundaries.  You will need to zoom in a good bit to see the state waters and their boundaries 0-3 miles from shore.

So to recap:  It is self-evident that a state bird list can only consist of birds recorded within a state’s legally defined boundaries (whether on land or at sea).    It should also be self-evident that a Bird Records Committee cannot change a state’s legally established boundaries at sea (AKA pelagic borders) any more than it can change a state’s legally established borders on land.   Since U.S. law stipulates that boundaries from 3-200 miles offshore are assigned to states via the principle of equidistance (closest point of land rule), then any bird records committee who fails to use this yardstick is at odds with the law and U.S. government policy (by which states are bound to observe).

Bottom line:  states (and therefore state BRCs) have no say in determining their boundaries in federal waters.  State waters and their boundaries are also a matter of law and have been thoroughly enumerated over the years.  So any BRC pronouncements about offshore boundaries are moot.  Such boundaries are already well-established, clearly defined, and a matter of law (even if the birding community is largely unaware of such facts).  Therefore all pelagic bird records should be submitted to the BRC of the state with jurisdiction over the nearest point of land.

Besides being legally correct, an added benefit of the closest point of land rule is that it is very simple and easy to apply, and it yields unambiguous results. Coming to grips with states’ true + legal pelagic borders will undoubtedly cause angst among birders from certain states who are on the short end of the law.  But states like Georgia and Rhode Island are still in much better seabirding shape than Nebraska.


Nate Dias, of Charleston, South Carolina, is SC’s top lister (life list and big year), has been a pelagic birder since the 1980s, and has organized pelagic trips out of Charleston off and on since the early 1990s.  His “day jobs” have included gigs as MIS Director for the Democratic National Committee, designing secure systems and networks for Wells Fargo Bank, and system engineering roles at multiple dot-coms.  He is also the director of the Cape Romain Bird Observatory, member of multiple bird conservation working groups, past member of the SC BRC, and past  SC Reviewer for project eBird.