Part
2, Sec. 2C4
Human Activities - Commercial Shipping
Vessels
crossing Stellwagen Bank come from two principal sources. The
first is vessels arriving at and departing from Boston Harbor.
There is an established Vessel Traffic Separation Scheme (VTSS)
recommended for this approach to Boston Harbor (Figure 8). The
VTSS originates in the Great South Channel, heads in a northerly
direction until just off the easterly side of Provincetown (Buoy
"BD"), where it proceeds in a northwesterly direction, crossing
the Bank, and ending in a Precautionary Area off the entrance
to Boston Harbor. The second source of vessel traffic across
the Bank is from the Cape Cod Canal. Based on data provided
for the Port of Boston by the Boston Shipping Association, and
a review of data logs from the Cape Cod Canal Field Office of
the U.S. Army Corps of Engineers, for the twelve month period
May 1989 to May 1990 (Table 7), approximately 2700 vessels crossed
Stellwagen Bank (average of about 225 trips per month). About
half of the vessels crossing the Bank are carrying liquid petroleum
products. The remainder of the cargo volume is made up of bulk
materials (e.g., asphalt, gypsum, cooking oils), containers,
fish, scrap metals, and automobiles. The Port of Boston is also
visited by a small number of cruise ships, research and military
vessels. Vessel activity does not appear to vary much seasonally.
While fluctuations have occurred, and will probably continue
to occur periodically, it is likely that shipping activity in
and out of the Port of Boston will remain relatively stable,
and be dominated by the movement of petroleum (Edward O'Leary,
COE/NED, pers. comm., May 1990). Despite the proposed deepening
of portions of the Harbor to be completed by the mid-1990's
and the worldwide trend toward larger vessels, it is unlikely
that significantly larger vessels will use Boston Harbor.
Cruise
ships currently comprise only a small part of vessel traffic
using the Port of Boston, averaging about 30 visits per year.
However, given the presence of a new state-of-the-art terminal
(Black Falcon Cruise Terminal on the Reserved Channel), the
Port could support significant expansion in this area. The Massachusetts
Port Authority (Massport), Maritime Department has suggested
that the numbers of cruise ships visiting Boston could be increased
considerably with appropriate promotion of the Port as a point
of departure for cruises to other ports to the north, particularly
maritime Canada; and as a base for "cruises to nowhere" (Anne
Aylward, Maritime Division, Massport, pers. comm., May 1990).
A possible seagoing ferry link to Halifax or some other Nova
Scotia port has also been discussed.
Given
the dominance of petroleum products as cargo of vessels passing
over Stellwagen Bank, the principal threat, at least theoretically,
is oil spills. Because the Bank, as a geologic feature, occurs
at much greater depths than safe navigational depths for all
vessels that might pass over it, spills caused by grounding
are not an issue. With the Vessel Traffic Separation System
having been in place and operational for a number of years,
the possibility of oil spills resulting from vessel collisions
is very minimal.
The
Coast Guard maintains at least two different historical oil
spill data bases. The Coast Guard Management Information Branch
in Washington has identified, for an area which includes the
shipping lanes across Stellwagen Bank (but not the entirety
of the study area), seven oil discharge incidents for the years
1988 and 1989. All reports involved fishing vessels, and only
two yielded observable discharges, totalling approximately 52
gallons. The USCG Marine Safety Office in Boston has identified
six incidents in the past 10 years, within an area somewhat
larger than the study area, involving no observable discharges.
To
estimate the possibility of vessel collisions causing oil spills,
vessel accident records, maintained by the Coast Guard Marine
Safety Evaluation Branch in Washington, were consulted. For
the period 1984-1988, there were a total of 105 so-called "vessel
casualties" reported for the study area. Of this total, nearly
all reports (98) involved fishing vessels; five were pleasure
or passenger vessels; and two involved commercial vessels (tugs).
Only two incidents were reported as collisions, both involving
fishing boats. Given the volume of ship traffic crossing the
Bank, these historic data indicate that the chance of a vessel
collision on the Bank appears to be quite remote. The prospects
of a significant oil spill are even less.
Chronic
discharges of oil from tank washing and ballast discharge is
also a potential source of contamination. Grossling (1976) has
suggested that, where large numbers of petroleum tankers and
barges are present, such discharges can be a significant source
of oil in the marine environment. However, it is not thought
that tank washings or ballast discharges occur in the vicinity
of Stellwagen Bank (Robert Calder, Executive Director, Boston
Shipping Association, pers. comm., May 1990). Coast Guard Oil
Regulations (33 CFR 157.37) prohibit the discharge of an "oily
mixture" (i.e., mixture of oil and water from tank washing and/or
ballasting) unless the vessel is at least 50 nautical miles
from the nearest land.
"Lightering",
described as the ship-to-ship transfer of petroleum products,
is an additional potential source of contamination. This activity
is regulated under the authority of the Federal Water Pollution
Control Act, as amended by the Clean Water Act of 1977 (33 U.S.C.
§§ 1251 et seq.). Relevant sections
of the Act have recently been amended by the Oil Pollution Control
Act of 1990 (33 CFR § 2701). Lightering is conducted to
transfer petroleum products onto smaller, shallower draft vessels
which are able to enter harbors not able to accommodate larger
commercial vessels. This activity occurs within Boston Harbor,
and in Broad Sound, immediately east of Deer Island, near the
entrance to the Harbor. When lightering is scheduled to occur
within the "anchorage" (the major deep draft area within Boston
Harbor), ship operators are required to provide four hours'
notice to the U.S. Coast Guard.
Lightering
is not known to occur on a routine basis within the area of
Stellwagen Bank. (LCDR George Matthews, Marine Safety Office
USCG, Boston, MA, pers. comm., June 13, 1991).
Routine
discharge of other materials (garbage, refuse, and other debris)
could also present potential problems. Although the Coast Guard
regulates such discharges under the Marine Plastic Pollution
Research and Control Act, which implements Annex V of the International
Convention for the Prevention of Pollution from Ships (MARPOL),
these regulations would allow the dumping from vessels of most
forms of refuse, with the exception of plastics and garbage
that floats, on all or part of the Bank (depending on the type
and character of the material involved). Certain vessels, such
as those of the military, have exemptions from any prohibitions
on dumping imposed by these regulations. While a vessel in transit
from Boston to Portland was recently fined $12,000 for discharging
refuse (in this case, dunnage), in an area directly adjacent
to the study area boundary, there is no estimate available as
to how much material is currently being discharged from ships
passing over Stellwagen Bank.
Another
potential issue of concern involving the shipping industry is
the potential for vessel collision with marine mammals. The
Draft National Recovery Plan for the Northern Right Whale (NMFS,
1990) devotes significant attention to the problem of marine
mammal collisions with vessels. The report states that over
the last two decades, twenty five right whale mortalities have
been documented, with five (20%) attributable to ship collisions.
One such mortality was reported over Stellwagen Bank. Approximately
24, or 8% of the 300 North Atlantic Right Whales identified
in the New England Aquarium's photographic catalog exhibit marking
presumed to be indicative of vessel collisions, although the
size and characteristics of vessels likely to have been involved
in these collisions are not definitively known. (Kraus, Crone
and Knowlton, 1988).
The
potential for possible collisions arises because right whales
exhibit behaviors such as resting at the surface, surface skim
feeding, and surface courtship, which increase exposure to possible
vessel collisions. In addition, because right whales are a relatively
slow swimmers, avoiding an approaching vessel is sometimes impossible,
particularly at night when visibility is reduced.
The
Plan identifies the reduction of vessel collision-related mortalities
as one of its implementation priorities. Two principal recommendations
are made to deal with this problem. The first is to identify
responsibilities related to reducing ship collisions with northern
right whales. This is to be accomplished by: 1) collecting additional
information regarding areas and seasons of potential conflict,
and characterization of the types of vessel typically involved
in ship collisions; and 2) analyzing known kills and scarring
patterns on living northern right whales to identify vessel
activities which put whales at risk of collision. The second
priority is to investigate strategies for reducing ship collisions
with right whales. To implement these objectives the Recovery
Plan proposes to: 1) educate mariners about right whales through
publishing special warnings, identifying seasonal high-use areas
in Coast Guard and Defense Mapping Agency Notices to Mariners
and VHF radio Marine Information Broadcasts; identifying those
areas on nautical charts; and 2) implement appropriate controls
on ship operation and design.
This
final objective involves activities such as:
a)
restricting vessel speeds in "high risk" areas during "high
risk" periods; b) requiring lookouts on ships during these "high
risk" periods; c) shifting shipping lanes where feasible; d)
placing acoustical warning devices on ships, if feasible; e)
using appropriate technologies to detect whales in the path
of vessels (e.g., side-scan sonar, low light intensity television);
f) investigating alternative vessel designs to reduce probability
of collisions; and g) investigating satellite capabilities for
the detection of transmitter-tagged whales in shipping lanes.
The implementation of the "ship collision" objectives of the
Recovery Plan are identified by its authors as a top priority.
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