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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