Evaluation by NEFMC's HAPC Plan Development Team of the Cashes Ledge HAPC Proposal : (proposed by Ocean Conservancy)

Overview
This proposed HAPC (Figure 7) seeks to extend the boundaries of the Cashes Ledge Habitat Closed Area in order to include deeper water habitats and ridges associated with Cashes Ledge. Cashes Ledge is a submarine mountain chain located in the central Gulf of Maine. The peak of this submarine mountain chain (Ammen Rock) rises to within 80 to 100 feet of the ocean surface.

This topographic feature in the middle of the Gulf of Maine creates a unique environment where nutrient-rich waters from the Gulf of Maine current rise up into the photic zone. The result is an incredibly diverse habitat area with a relatively intact ecosystem including high densities of phytoplankton, lush kelp forests, a diverse invertebrate community, and an assemblage of predatory fish, marine mammals, and seabirds.

Cashes Ledge is also known to contain one of the deepest seaweed communities in the world. The ocean currents and internal waves surrounding Cashes Ledge give rise to a self-recruiting system. The unique oceanographic characteristics and habitat features found in the area satisfy many of the HAPC designation criteria, including importance of ecological function, sensitivity to human-induced degradation, and rarity of habitat type.

Step 1: Does the proposed HAPC meet the criteria established under the EFH Final Rule?
The PDT evaluation concludes that the proposal satisfactorily meets the EFH Final Rule criteria: 1(B) (Importance of Current Ecological Function), 2 (Sensitivity to Anthropogenic Stresses) and 4 (Rarity of the Habitat Type).

Step 2: Does the supporting information justify the HAPC designation?
Generally, the PDT felt that the information provided in the proposal justifies an HAPC designation. However, although the proposal correctly describes field studies done at Ammen Rock, it extrapolates the results of gear effects studies done in other parts of the Gulf of Maine and applies them to Cashes Ledge. However, some PDT members approved of concluding that a study of trawling effects on kelp or other attached plant or animal growth anywhere else would apply to Cashes Ledge.

The proposal correctly identifies bottom trawls and dredges as gear types that are known to adversely impact benthic habitats, especially hard-bottom habitats that support well-established attached epifaunal communities, and seeks to extend the types of gear of concern to fixed gear, but the supporting information for this is weak. Since the inferences linking habitat to potential fish production came from studies in other parts of the Gulf of Maine, there doesn't appear to be site-specific data to support strong management action.

In reference to the following justification paragraph in the proposal, the PDT has concerns:

"Finally, the Cashes Ledge area has been identified as an area believed to contain deep-water corals. Wigely (1968) describes Paragorgia as a common component of the gravel fauna of the Gulf of Maine and stated that representative gravel fauna occurred on "Cashes Ledge, parts of the Great South Channel, the northeast part of Georges Bank, western Browns Bank, Jeffreys Ledge, and numerous other smaller banks in the Gulf of Maine region". The presence of deep-water corals in the area is another unique characteristic of the Cashes Ledge area."

The PDT felt that the proposal makes a tenuous connection to corals with the Wigley data as the data do not contain deep-water coral observations from Cashes Ledge but rather that Cashes contains representative gravel fauna. The PDT felt that the first sentence should be removed from the justification.

The PDT also felt uncomfortable with the lack of support for the claim that Cashes Ledge supports an "unusually high abundance of large-bodied predators such as cod, wolffish, pollock, and sharks ". This paragraph needs to be re-worked to make certain there is abundant justification (Whitman and ??? 1992).

Step 3: How strongly does the information support the application?
The proposal is generally well supported by site specific studies on the ecology of the benthic community at Ammen Rock; inferences from gear effects impacts on EFH from other parts of the GOM and speculations on the oceanography of the region and it's linkage to the ecological structure/function of the benthic habitats in the proposed HAPC. The PDT did note that the figure showing the location of the proposed HAPC is inadequate and needs to show the boundaries of the HAPC in relation to the existing groundfish and habitat closed areas.

Step 4: Evaluation of the HAPC based on the criteria and preferences set forth by the Council
The proposal addresses the Council priorities for: EFH designation for more than one NEFMC managed species and addresses three of the EFH Final Rule HAPC criteria. The major factors in favor of this HAPC proposal are habitat rarity of hard substrates (4) and large biomasses of epifauna and kelp in this substrate type which may be susceptible to mobile fishing gear (2).

According to the proposers, EFH for the following species is designated within the boundaries of the proposed HAPC juvenile and/or adult life stages of Atlantic cod, haddock, pollock, monkfish, American plaice, white hake, witch flounder, and halibut. The text description for these species should be evaluated by the PDT as well as any change in EFH representation caused by the boundary shift recommended by the PDT (step 5).

Management measures have not been recommended as part of this HAPC proposal. As proposed, it would not change fisheries management in the EEZ. However, the proposers have

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requested that a full range of alternative measures, including area-specific closures, gear requirements, and effort reductions be considered at the appropriate point. Specifically, they request that the Council develop a range of alternatives for this HAPC proposal and that the analysis include evaluation of Level I, II, and III habitat closures (as defined in Amendment 13 to the Groundfish IMP) and that the impacts analysis specifically evaluate the potential benefits to habitat function, fish productivity, and overall ecosystem health. The PDT has not evaluated these requests at this point.

Step 5: A report of all proposal applications reviewed which would include: The grades and notes for each proposal that went through Step 1- Step 4, and a record/reason for any proposal received but not reviewed (incomplete, awaiting more information, etc.).

The proposal seeks to extend the types of gear of concern to fixed gear, but the supporting information for this is weak. The rarity of hard substrates in the central Gulf of Maine provides a rationale for management action, in light of the impacts of mobile fishing gear on the physical/biological structure provided by rocky bottom substrates on the ledge. Although not a criteria, it is not clear from the proposal whether this rare habitat types/aggregations of epibiota provide a "recruitment bottleneck" for any Council Managed species.

The proposal does meet three of the four HAPC criteria (1, 2 and 4), includes juvenile cod EFH (needs to be verified based on the text description) and EFH for more than one Council- managed species.

Step 6: Outcome
The PDT believes that this proposal has merit for further consideration as a HAPC alternative but could be improved by a careful review of the supporting information and its relevance to the proposed HAPC and the management actions that may be required in the future. The PDT would like to recommend alternative boundaries that would exclude the muddy areas to the east and west side of the currently proposed boundary. This will be based on bathymetric fishing charts as well as NOS special bathymetric data.

The fact that Cashes Ledge provides an extensive area of hard substrate in fairly shallow water in the central Gulf of Maine, thus including rare habitat where more dense and diverse species aggregations are observed as compared to the surrounding deep, open-water habitats, is the strongest argument in favor of considering this area as a HAPC. The fact that Cashes Ledge has already been selected as a site for a habitat closed area further strengthens its candidacy as a HAPC.

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