SEARS ISLAND CARGO TERMINAL

MARINE RESOURCES IMPACT ASSESSMENT
Prepared by Normandeau Associates

DESCRIPTION OF THE ACTION
EARLIER ACTIONS CAUSEWAY, DREDGING, JETTY
POST ACTION ALTERNATIVES
D.1 SOLID FILL
D.2A SOLID FILL WITH NORTH ACCESS
D.2D.

SECTION 4.0 EELGRASS
SECTION 5 BENTHIC
SECTION 6 FISHERIES RESOURCES
SECTION7 PRIMARY EFFECTS ON
SECTION 8 MARINE WILDLIFE
SECTION 9 RARE, THREATENED OR ENDANGERED MARINE SPECIES
SECTION 10 SECONDARY AND CUMULATIVE IMPACT

Evidence that eelgrass has occurred in the Long Cove area historically is presented in the EIS. In 1975 CMP did an extensive survey of marine resources in the waters surrounding Sears Island. Included in the survey were investigations into the distribution and production of eelgrass.

Beds of eelgrass were mapped in Long Cove in Sept 74 and mid June 1975. and at the head of Stockton Harbor in mid June 1975 Beds in both areas extended from the mean low water (MLW) to about 12 ft.

Transect was examined in the vicinity of Sears Island and no eelgrass was reported in 1990. Members of the Sears Island Marine resources technical team ( MDOT MDMR, NMFS, EPA & Normandeau) convened to develop appropriate protocol to evaluate existing eelgrass conditions in the area. Low tide aerial photographs of the western shoreline of SI in 1990 August; evidence of eelgrass was inconclusive.

The area encompassing alternative project locations, the northwest option of Sears Island, was examined for eelgrass in August 31, 1992 Maximum depth for eelgrass was expected to be 18 ft.

This was assumed to be the seaward boundary of the survey.

Field personnel from NMFS EPA were split into 3 groups. two waded along the shoreline. Mid depth was observed with viewbox and snorkel.

The substrate offshore consists predominately of a silt or sand matrix with varying proportion of gravel, cobble, mussels boulders and

Eelgrass was observed even in the wave action areas. Not observed in depths greater than 7 ft

Eelgrass categories greater than 1/2 meter between shoots = sparse. Small patch = shoot densities were greater. Densely vegetated patches were approximately .5 meters in diameter; large patch category where the vegetation was uniformly distributed but the substrate was clearly visible. Very dense category where eelgrass dominated the field of vision.

August 1992
Eelgrass beds along the Sears island shoreline provided habitat for other organisms, including starfish, mussels, and snails were observed. Winter flounder, cancer crabs, green crabs and starfish were observed in the vegetated areas. Epiphytes occurred on some fronds.

Discussion. Distribution of eelgrass in the vicinity of Sears Is is probably limited by light penetration, rather than other factors. The lower depth for 1992 was approx ¬7 Eelgrass occurred in most substrates types identified in the nearshore area. Substrate conditions in conjunction with current regime may partially account for the varied distribution.

Fonseca et all 1983 distinguished 3 current regimes:
Low <50cm/sec;
Medium >50 but <90;
high: >90 centimeters per second:

the maximum amount of surface velocity that controls sedimentary conditions on eelgrass beds. He found low currents allowed even distribution of silt/clay particles..... suggests the entire perimeter of sears island except portions of the easter side where currents are much faster and the substrate slopes abruptly, is eelgrass habitat. In fact eelgrass has been observed on the north eastern, eastern and southern sides of the island during other surveys in 1982.

Similarly, shallow areas in Long Cove, Stockton Harbor and the entire Searsport shoreline are potential eelgrass habitat. Historic presence of eelgrass: 1975 one acre in Long Cove and 3 acres in Stockton Harbor. In 1976 eelgrass was found only in the at the head of Long Cove.

Divers observed no eelgrass around Sears Island at that time. Eelgrass was reported to be virtually absent from the northwestern shoreline of Cape Jellison during the 80's , but present in dense stands in 1991¬92. (NAI 1992a) The same pattern occurred in Long Cove.

Wasting disease was documented as contributing to extensive dieback of eelgrass in southern Maine and New Hampshire in the 80s. May have been a factor in population shifts in Penobscot Bay. The presence of diseased shoots within the bay indicates wasting disease could have been present in 1992. Dead leaves float out of the bed and usually are carried to the wrack line. Wasting disease tends to cause a release of internal gases; dead leaves tend to sink rather than float.

Eelgrass has occurred throughout most waters of the state of Maine. The Maine Wetlands Conservation Plan of 1988 estimated the extent of eelgrass in the state as between 8,931 to 11,000 acres. The Maine State Planning Office considers the resource to be stable, except for the effects of dragging and wasting disease.

DMR is in the process of sampling the eelgrass resources of Cobscook Bay, Penobscot Bay and Casco Bay. According to S Barker DMR 2/2/94 personal communication to NAI. Eelgrass resources in Penobscot Bay were identified

From Impact Assessment

Section 4.0 Primary impacts on eelgrass. As indicated in the Sears Island Marine resources baseline report eelgrass beds occur along the northwestern shoreline of SI although densities were not quantified, field observations indicated distribution was not homogeneous in the area examined in 1992. Deepest occurrences of eelgrass was observed at ¬7 ft. Because all substrates within the study area, except ledge supported at least scattered strands of eelgrass, the entire study area between MLW and ¬7 ft was considered as potential eelgrass habitat

Assessment of direct impacts makes no distinction between documented and potential eelgrass habitat and among areas of apparently different densities. The distinction was made between vegetated and non vegetated eelgrass habitat for the assessment of some secondary effects.

Secondary effects associated with the alternative wharf configurations generally related to water clarity, sediment erosion and deposition, current and wave velocity. These factors could affect primary production and sediment stability. Water clarity would not affect plants that are present, as short duration changes in water quality would have no effect on potential eelgrass habitat. Sedimentation could prevent establishment of eelgrass plants in areas that provide potential habitat. Structure or operation induced current and wave velocities sufficient to erode sediments could affect potential eelgrass habitat, especially if recruitment was dependent on seeds, rather than vegetative reproduction. This distinction will be included in the evaluation of each alternative wharf design.

Section 4.1.1.1 causeway Eelgrass occurred in intertidal pools along the natural bar between Kidders Point and Sears Island prior to construction of the causeway. Examination of preconstruction aerial photographs indicated eelgrass occurred in two tidal pools approx 5700 square feet and 580 square feet based on interpretation of aerial photographs... These intertidal eelgrass beds were lost as a result of building the causeway.

Since completion of the causeway in 1989 is has been noted that natural reestablishment of small patches of eelgrass in tidal pools along the east side of the causeway. These patches aren't readily discernable in aerial photographs, but they have been observed from the ground. Robertson & Mann 1984 & Bayer found intertidal zones supported eelgrass as an annual, rather than perennial form Dependence on growth from seeds can result in high variability in bed size and density. Over the years, it seems to have been the case along the causeway.

Section 4.1.1.2 DREDGING The previously dredged area angles out from the Sears Island Shorelines at the north end of the dredged areas closest to the shoreline.. (approximately 0.2 acres)

To the near shore dredge area for cell construction? was located shallower than ¬ 7ft Identified in 1992 as a limiting factor for eelgrass locally. This dredging resulting in the direct loss of this eelgrass habitat.

The Rockland disposal site was located in depths greater than ¬221 feet. Well below the zone that eelgrass occurs.

SECTION 4.1.1.3 JETTY The jetty, constructed in 1988, covers an area of 2500 square feet between MLW and ¬7ft mean water Including 6,100 feet squared in the dredged area. The jetty occupies an area of 0.2 acres of eelgrass and potential eelgrass habitat .

SECTION 4.1.2 SECONDARY EFFECTS

4.1.4.2.1 CAUSEWAY Filling operations on the causeway only took place during low tides, minimizing the likelihood of dispersion of fill from the work area. It is unlikely that prolonged turbidity developed as a result of construction. Small tide pools have formed along the eastern toe of the slope of the causeway that have been vegetated with eelgrass to varying degree since the causeway was completed.

4.1.2.2 DREDGING Turbidity induced reduced photosynthesis occurred as a result of the dredging. The extended periods of dredging during seasons when eelgrass growth most typically occurs can be systemized Eelgrass in the present: turbidity from dredging contributed to limited production in an area of 2.5 acres reduced production in 7.6 acres. Eelgrass was not present when dredging occurred. Turbidity Plume could not have impacted potential eelgrass habitat Unless they were highly depositional areas where a high rate of sedimentation prevented successful recruitment.

It is unknown whether it was present in the northwestern shoreline of Sears Island when dredging was initiated. The presence of eelgrass in the study area in August 1992 indicated dredging did not create any permanent impacts deleterious to eelgrass.

4.1.2.3 JETTY Eelgrass was present north and south of the jetty during the 1992 survey though the area adjacent to the south side of the jetty near Mean Low Water MLW appeared to be depositional with soft finegrained sediments predominating. Locally elevated turbidity or deposition could prevent vegetation of eelgrass.

Thus potential eelgrass habitat has been lost. The shallow subtidal area between the jetty and the protrusion of the mean low water contour about 500 feet to the south was characterized as silt cobble substrate with sparse eelgrass during baseline survey. This type of substrate is not indicative of deposition

The relatively sparse vegetation could reflect the combined influences of substrate and back eddy instability. This area is approximately 2.2 acres of potential reduced production.

page 111 SUMMARY Section 4.3 Primary impacts to eelgrass andpotential eelgrass habitat under each alternative configuration are summarized in Table 4.3 (obtained).

There will be no differences in impacts to eelgrass among the alternatives related to the Earlier Action. Alternative D.1 would have a larger direct effect on eelgrass 11.3 acres) than any of the D¬2 Alternatives.

Differences in "footprint" among the D¬2 alternatives would be small. D¬2b and D¬2(c) have the greatest footprint in eelgrass habitat because of the culverted north areas D¬2(A) and D2(D) having the same footprint on this resource (0.2 acres) and D¬2(E) having the smallest footprint because of its placement of the intertidal structure on the piles (0.01) acres.

SECONDARY EFFECTS OF CONSTRUCTION are most closely linked to turbidity generated during dredging. Because of the larger volume and longer duration of dredging Alternative D1 will have a greater impact, albeit temporary, on eelgrass resources than any of the D2 Alternatives.

Alternative D-2 A, B and C would have greater impacts by the same token than alternatives D-2 D &E. Its relative to the amount of filling and piling would also affect different turbidity generation which could differ among alternatives. These differences are not presently quantifiable.

OPERATION OF THE CARGO TERMINAL could also cause secondary impacts to eelgrass resources. Areas of reduced wave energy, elevated current velocity due to vessel maneuvering, shading and scour at the base of riprap were identified as lost habitat. Alt D¬1 would result in the loss of 7.4 acres of eelgrass habitat resources D¬2 A&D would impact 5.6 acres of eelgrass habitat. D¬2 B& C would affect 5 acres of eelgrass habitat. D2 E would affect 4.5 acres of eelgrass habitat.

Areas affected by increased turbidity or sediment deposition are more difficult to predict, particularly because potential sediment release rate from construction activities and vessel maneuvering needed to estimate suspended sediment concentrations is unknown.

Figures 4¬3 areas are unknown. For alternative D¬1 This represents about 27.4 acres D2D: 29 acres; back eddies from alternative D¬2 A,B or C wharf construction could extend over a 9.9 acre area. Alternative D2E would be unlikely to generate a larger area impact base than undeveloped. No jetty conditions. Loss of eelgrass, potential eelgrass habitat due to filling, erosion, dredging or deposition or reduction in productivity due to turbidity or shading can effect the functions and values of the eelgrass beds along the northwest shores of Sears Island.

Direct loss of the resource would eliminate most functions presently provided by the eelgrass although man made structures could support other types of flora and fauna adapted to hard substrate conditions.

Construction and generated turbidity could affect the functional value of the eelgrass bed within the turbidity plumes. As long as the rhizome system remains intact, the eelgrass beds can continue to stabilize sediments. Under conditions of prolonged high turbidity, plants would die and function would cease. Dredging would create a plume of relatively short duration. Wharf construction would generate turbid conditions intermittently. It would be unlikely these activities would result in complete leaf loss. Thus the bed would maintain its ability to trap sediments.

This, however, could lead to higher than normal rates of deposition, because of a greater source of suspended particles. Reduction of photosynthesis due to reduced light conditions from shading or extensive turbidity would reduce eelgrass productivity and stressed eelgrass ecosystems. Annual production would be lower than without construction.

Effects, if any, of turbidity generated by construction on the ability of the affected eelgrass beds to support fish would be temporary. Fish vary in their response to turbidity. Demersal species are generally more tolerant of turbid conditions than pelagic species. Shoreside fish likely to occur in the area Rainbow smelt, atlantic silverside, alewife, 3 spined stickleback, blueback herring, could avoid the turbid area, thus there could be a temporary reduction in finfish utilization of the affected eelgrass bed.

Filterfeeding invertebrates associated with eelgrass could experience clogging. Motile species such as sand shrimp, crab and lobsters could leave the area or burrow into the substrate to avoid turbidity. Bivalves could temporarily cease feeding. There could be a temporary reduction in abundance or diversity of fish or invertebrates.

The ability of eelgrass to support wildlife is primarily waterfowl

MARINE OPERATIONS AT THE CARGO TERMINAL pg 17 of impact assessment section

2.4. MDOT anticipates the proposed cargo terminal could service 80 to 90 ships per year, about 8 ships per month:

one container ship every 1 1/2 weeks, one breakbulk ship every 2 weeks one woodchip ship every 2 1/2 to four weeks

Container ships remain in port about 1 day, while breakbulk and woodchip ships remain in port about 2¬3 days.

Docking at the facility could be accomplished with or without tug service. As with all other commercial traffic operating in Penobscot Bay, cargoships using the proposed facility would be accompanied by a local pilot. Requirement for tugs would be up to the local harbormaster, weather and sea conditions. When a tug is involved, the ship will use minimum power during approach and departure to the port. Usually the ship will turn around north of the terminal so it can dock heading south. The ship would stop parallel to the wharf and allow the tug to push it broadside into the dock.

To assist the ship in leaving the wharf, the tug would pull the ship off. The tug would be angled, heading seaward. Running at slow prop speed, the ship would deflect most of the current created by the tug propeller, but create its own shoreward current. Unassisted, a ship would likely loosen its bow lines, swing its bow out. With the ship's stern angled toward the wharf, the rudder would partially deflect currents emanating from the propeller.

The magnitude of the propeller generated current heading toward the shore would depend on the ship's angle, propeller shaft power, and the speed and direction of tidal currents. The likelihood that these currents would erode sediments and cause turbidity would depend on the substrate condition, elevation of the propeller, ships draft and tide level.

Containers ships could use bow thrusters, breakbulk ships could use mid ship thrusters to push themselves off the wharf. In this event, currents would be directed nearly perpendicular to the shoreline. Bow thrusters are generally of short duration thrusts of power. The ship would have its main propeller turning at slow speed when using thrusters.

SECTION 6.6 IMPACT REPORT PG 146 SUMMARY OF EFFECTS ON FISHERY RESOURCE
The overall project effects on fishery resources are summarized, based on resource function and values presumed to be affected during the Earlier and Proposed Actions.

Prior to the construction of the causeway, the intertidal bar probably provided some level of functionality for aquatic biodiversity/abundance. (feeding breeding and refuge) and wildlife diversity/ abundance (feeding , breeding and refuge) of fishery resources as described in NAI 1994.

Those benthic and pelagic resources physically displaced by the placement of the causeway are permanently lost. The previous construction of 1.3 acres of mitigated clamflats should provide functional opportunity to replace those functions physically displaced by the causeway.

Stabilizing and armoring the causeway during construction has provided potential intertidal feed/ breeding/refuge habitat for both hard and soft substrate benthic fishery organisms, e.g.,shellfish, crustaceans, worms and sea urchins and some finfish. Changes in area hydrology may allow for the accretion of sediments transported along the post construction shoreline. (Since dredging the basin did not permanently displace subtidal resources, it is anticipated no long term impact to subtidal functions occurred). These functions also include: aquatic diversity/abundance, (feeding, breeding, refuge) and wildlife diversity abundance (feeding/breeding /refuge).

While the stone jetty physically displaces 0.3 acres of intertidal shoreline and 0.2 acres of subtidal resources, it is assumed that functional resource values were modified from benthic habitat function significant to soft substrate organisms to those more significant to hard substrate organisms.

Effects on small surface areas are not easily translated to changes in functional effectiveness or opportunity.

Proposed additional dredging under all proposed alternatives should not permanently displace subtidal resources again,it is anticipated no long term effects to the subtidal fishery or benthic or pelagic fishery functions described above would occur. The previously dredged basin contains a previously offed? condition which has undergone somewhat of restoration through natural recruitment.

In the D¬1 solid wharf configuration direct displacement effects would reduce the water column and benthic habitats of both intertidal and subtidal fishery resources. These impacts would be comparable to those impacts discussed in Section 5.3.

SECONDARY EFFECTS associated with changes in hydrodynamics, turbidity and sediment deposition could also affect several acres of intertidal and subtidal fishery resources and their associated functions and values. The specific concern, regarding secondary effects in all proposed wharf alternatives would be settleable solids and their smothering effect on sessile organisms and locally breeding finfish. what about the eggs, larvae and juveniles? All three are more sensitive to suspended solids than adult fish.

As stated in NAI 1994, any of the area utilized for spawning by Atlantic Herring Winter Flounder american sandlance, rock cunnel, tomcod and sculpins. These species represent potential food stocks for large carnivorous finfish and potentially valuable commercial and recreational stocks.

End of scanned document. -------------------------------------

END

================================================

Back