The coastal zone, broadly defined
as near-coast waters and the adjacent land area, forms a dynamic
interface of land and water of high ecological diversity and critical
Change Impacts and Adaptation: A Canadian Perspective
The zone includes the beach, estuaries, the adjacent land
draining directly into the coastal waters, and the offshore waters, usually
out to the edge of the continental shelf. The physical characteristics
are described in Types of Coasts.
- Many people live in the coastal zone. Overall 38% of the world's
population lives within 100 km of the coast or estuaries, and 44% live
within 150 km of the coast..
- The number of people living within 100 km
of the coast increased from roughly 2 billion in 1990 to 2.2 billion
in 1995—39 percent of the world's population. From World
Resource Institute, Earthtrends.
Thus, each year roughly 50 million more people move into the coastal
- The coastal zone is important because it is a source of fish and
- The coastal zone is an
important political entity.
What are coastal waters, and who controls what is done on and below
the coastal waters of any country? These are very old questions, and
the nations of the world have agreed to some extent on some answers.
- Each coastal nation can claim jurisdiction over all activity in a
narrow band of ocean close to shore, the territorial sea.
- Each coastal nation can also control economic activity in a wider
band of water called the Exclusive Economic Zone.
Here we will briefly consider the international framework,
the laws of the United States, and the laws of the State of Texas.
The extent of each coastal country's territorial sea is
defined by the UN
Convention on the Territorial Sea and the Contiguous Zone, 1958 (click
on the link near the top of the page to download a 200-KByte pdf file
with the text of the convention).The UN also has a very interesting web
page that puts the convention into an historical
context. The following articles are taken directly from the Convention
(note State refers to a country).
- The sovereignty of a State extends, beyond its
land territory and its internal waters, to a belt of sea adjacent to
its coast, described as the territorial sea.
- The sovereignty of a coastal State extends to
the air space over the territorial sea as well as to its bed and subsoil.
- Except where otherwise provided in these articles,
the normal baseline for measuring the breadth of the territorial sea
is the low-water line along the coast as marked on large-scale charts
officially recognized by the coastal State.
- In localities where the coast line is deeply indented
and cut into, or if there is a fringe of islands along the coast in
its immediate vicinity, the method of straight baselines joining appropriate
points may be employed in drawing the baseline from which the breadth
of the territorial sea is measured.
- Subject to the provisions of these articles, ships
of all States, whether coastal or not, shall enjoy the right of innocent
passage through the territorial sea.
- The coastal State must not hamper innocent passage
through the territorial sea.
- In a zone of the high seas contiguous to its territorial
sea, the coastal State may exercise the control necessary to:
- Prevent infringement of its customs, fiscal,
immigration or sanitary regulations within its territory or territorial
- Punish infringement of the above regulations
committed within its territory or territorial sea.
- The contiguous zone may not extend beyond twelve
miles from the baseline from which the breadth of the territorial sea
US Presidential Proclamation 5928 Claiming A
12 Nautical Mile Territorial Sea For The U.S.
On December 27,1988, U.S. President Ronald
Reagan signed proclamation 5928, which claimed a 12 [nautical] mile
territorial sea for the U.S. As established by the United Nations
Convention on the Law of the Sea (UNCLOS), the territorial sea is
a belt of ocean which is measured seaward from the baseline of the
coastal nation and subject to its sovereignty. This sovereignty also
extends to the airspace above and to the seabed and subsoil. It is
exercised subject to UNCLOS and other rules of international law
relating to innocent passage, transit passage, archipelagic sea lanes
passage and protection of the marine environment.
Coastal Services Center
Exclusive Economic Zone
The exclusive economic zone is an area beyond
and adjacent to the territorial sea, subject to the specific legal
regime established in this Part, under which the rights and jurisdiction
of the coastal State and the rights and freedoms of other States
are governed by the relevant provisions of this Convention ... In
the exclusive economic zone, the coastal State has ... sovereign
rights for the purpose of exploring and exploiting, conserving and
managing the natural resources, whether living or non-living, of
the waters superjacent to the seabed and of the seabed and its subsoil,
and with regard to other activities for the economic exploitation
and exploration of the zone, such as the production of energy from
the water, currents and winds ... The exclusive economic zone shall
not extend beyond 200 nautical miles from the baselines from which
the breadth of the territorial sea is measured.
Convention on Law of the Sea
Boundaries of all Exclusive Economic Zones
of the world. Other maps are at the Sea
Around Us Project, which allows you to see the zone for each country,
and from VLIZ
Maritime Boundaries Geobase. Click
on image for a zoom.
Project of the University of Texas Medical Branch.
US Presidential Proclamation 5030 Creating The Exclusive
On March 10, 1983, U.S. President Ronald
Reagan signed proclamation 5030, which established the U.S. Excusive
Economic Zone (EEZ). This consists of those areas adjoining the territorial
sea of the U.S., the Commonwealth of Puerto Rico, the commonwealth
of the Northern Mariana Islands, and U.S. overseas territories and
possessions. The EEZ extends up to 200 nautical miles (370 km) from
the U.S. coastline. About 15 percent of this area lies on the geologic
continental shelf and is shallower than 200 meters. Within its EEZ,
the U.S. has sovereign rights over all living and non-living resources.
Other nations may exercise freedom of vessel navigation and over
flight within the U.S. EEZ (Source: Year of the Ocean Discussion
Papers 1998; 2nd Ed. of Coastal and Ocean Law by Kalo et al. 1994)
From NOAA Coastal Services Center
By the stroke of a pen and in an act that
cost the United States nothing, America had in essence more than
doubled in size. Debate continues over the exact size of the U.S.
EEZ, but it is probably around 4 million square miles ... the territory
around Hawaii alone is about 1 million square miles, or an area larger
than Mexico. Historically, this action is comparable to the Louisiana
Purchase of 1802. Yet because the seas draw so little attention,
this proclamation was hardly reported in the news.
From Wilder, R. J. (1998). Listening to the Sea: The Politics of Improving
Environmental Protection. Pittsburgh, University of Pittsburgh Press.
The largest Exclusive Economic Zone of the
USA is in the Pacific. Most of the Northwest Hawaiian Islands is
also a marine protected area. Click on image for a zoom.
From NOAA Pacific Islands Fisheries Science Center, Western
Pacific Fisheries Information Network.
Coastal Zone Management in the US and Texas
The Federal Coastal Zone Management Act of 1972 provided incentives
for coastal states to develop resource-management programs to regulate
The term "coastal zone" means the coastal
waters (including the lands therein and thereunder) and the adjacent
shorelands (including the waters therein and thereunder), strongly
influenced by each other and in proximity to the shorelines of the
several coastal states, and includes islands, transitional and intertidal
areas, salt marshes, wetlands, and beaches ... The zone extends inland
from the shorelines only to the extent necessary to control shorelands,
the uses of which have a direct and significant impact on the coastal
waters, and to control those geographical areas which are likely to
be affected by or vulnerable to sea level rise.
The term "coastal waters" means
... those waters, adjacent to the shorelines, which contain a measurable
quantity or percentage of sea water, including, but not limited to,
sounds, bays, lagoons, bayous, ponds, and estuaries.
Zone Management Act of 1972
The Marine Protection,
Research, and sanctuaries Act of 1972 regulated the dumping
of wastes into ocean waters, and it authorized the Secretary of
Commerce to designate national
marine sanctuaries for the "purpose of preserving r restoring
areas for their conservation, recreational, ecological, or esthetic
values." Originally, the sanctuaries had multiple uses, including
fishing and resource use. Lately, NOAA has started to create zones
within the sanctuaries where marine life is fully protected, although
fishing is still allowed in most areas.
A. Seaward Boundaries
Section 304(1) of the Coastal Zone Management Act defines the seaward
extent of a state's coastal zone as "to the outer limit of state
title and ownership under the Submerged Lands Act (43 U.S.C. 1301 et.
seq.)...." Under the Submerged Lands Act, Florida's title and
ownership extends three miles into the Atlantic Ocean and, in accordance
with United States vs. Louisiana, et. al., 364 U.S. 502 (1960), three
marine leagues (approximately nine miles) into the Gulf of Mexico.
Texas' title and ownership extends nine nautical miles. NOAA
But in no event shall the term "boundaries" or
the term "lands beneath navigable waters" be interpreted
as extending from the coast line more than three geographical miles
into the Atlantic Ocean or the Pacific Ocean, or more than three
marine leagues into the Gulf of Mexico, except that any boundary
between a State and the United States under this Act [43 USC § § 1301-1315]
which has been or is hereafter fixed by coordinates under a final
decree of the United States Supreme Court shall remain immobilized
at the coordinates provided under such decree and shall not be
From Section 1301—Definitions Submerged Lands Act.
B. Tidal Datums
The seaward extent of the various political divisions is from a line
on the beach determined by the height of the tides, called the tidal
datum. Mean Higher High Water (MHHW), Mean High Water (MHW), Mean Low
Water (MLW), and Mean Lower Low Water (MLLW) are examples of tidal
datums (i.e., vertical datums defined by a phase of the tide). In the
U.S., the MLLW is the baseline from which more seaward boundaries are
High and low tides used to define tidal datums.
A tidal day is the time interval between two successive passes of moon
past a place on earth, approximately 24.84 solar hours (24 hours
and 50 minutes). It is also called a lunar day.
From NOAA Special Publication NOS CO-OPS 1: TIDAL
DATUMS AND THEIR APPLICATIONS (2000).
High Water: Maximum height reached by
a rising tide.
Mean High Water: The average of all the
high-water heights observed over the National Tidal Datum Epoch.
Higher High Water: The highest of the
high waters (or single high water) of any specified tidal day.
Mean Higher High Water: The average of
the higher high water height of each tidal day observed over the National
Tidal Datum Epoch.
Low Water: The minimum height reached
by a falling tide.
Mean Low Water: The average of all the
low water heights observed over the National Tidal Datum Epoch.
Lower Low Water: The lowest of the low
waters (or single low water) of any specified tidal day.
Mean Lower Low Water: The average of
the lower low water height of each tidal day observed over the National
Tidal Datum Epoch.
National Tidal Data Epoch: The specific
l9-year period adopted by the National Ocean Service as the official
time segment over
which tide observations are taken and reduced to obtain mean values for
tidal datums. The present epoch is is 1983 through 2001.
Because sea level is changing, rising along most coasts, dropping along
Alaskan coasts, the tidal datum is recalculated every 20–25 years.
Simplified summary of US political boundaries within the coastal zone.
image for a zoom.
Geographic Data Committee's Marine Boundary Working Group, Shoreline
Boundaries Diagram (pdf file) linked from bottom of page.
C. Texas' Boundary
By 1975 the Texas Coastal Management Program had defined the Texas coastal
zone as "southwest along the coast from the Sabine to the Rio Grande,
seaward into the Gulf of Mexico for a distance of 10.35 miles (9 nautical
miles, which was originally 3 leagues under Spanish law), and inland
to include 36 counties." (Handbook
of Texas) This zone is composed of eight geographic areas extending
from the inner continental shelf to about forty miles inland. It includes
all estuaries and tidally influenced streams and bounding wetlands.
Texas regulates fishing out to 9 nautical miles, and the federal government,
through the Gulf of Mexico Fishery Management Council regulates fishing
from 9 to 200 nautical miles from the coast.
Texas Coastal Management Zone as defined by the Texas legislature.
Coastal Coordination Council
The total coastal zone of Texas comprises
an area of more than 33,000 square miles. The coastal counties have
one-third of the state's population, one-third of its economic activity,
40 percent of the national petrochemical industry, 25 percent of
the national petroleum-refining capacity, and three of the ten largest
seaports; yet they make up only about one-tenth of the total land
area of the state. The zone is richly endowed with natural resources.
Its mineral production, largely of oil and gas, has a value of nearly
$1 billion a year. Another $156 million comes from commercial fisheries.
The fertile soils along the coast produce agricultural products valued
at $500 million a year. The beaches and waters attract about three
million tourists who spend nearly $1.6 billion per year.
8 April, 2009