Letter: Unusual Mortality Events (UME) in Humpback and North Atlantic Right Whales

from Dr. David D. Dowd

Letter to the editor:

As a retired marine scientist and grassroots environmental activist living on Cape Cod, I have been concerned about this rising mortality in North Atlantic right whales (NARW) and Gulf of Maine humpback whales.  Following a meeting of the Atlantic Large Whale Take Reduction Plan in Providence, RI, NOAA Fisheries Greater Atlantic Regional Fisheries Office

(GARFO) has initiated  scoping meetings throughout New England.  This includes one in Bourne,  Ma. from 6-9 PM on August 21.

NARWs are on the endangered species list and the number of deaths from ship strikes/ fixed fishing gear entanglements has exceeded the number of calves born in recent years.

Their population has diminished to 400  animals by some estimates. Many of these deaths occur in their Summer feeding grounds in the Gulfs of Maine and St. Lawrence.  Their Winter breeding grounds occur off of the Southeasten US in areas proposed for oil/gas drilling or wind farms.  They feed on large zooplankton and tend to migrate to where their prey are abundant.  Research on the plankton community in the Gulf of Maine suggests effects from warming oceans offshore which could effect the growth and recruitment of calves.  The NOAA Fisheries GARFO scoping meetings are focused on interactions with fixed fishing gear (lobster and crab pots) and ship strikes in major shipping lanes (where speed restrictions  are in place when NARWs are present).  Politicians in Maine want to develop their own lobster pot restrictions that would allow fishing and reduce entanglements of NARWs.  The Marthas Vineyard Wind project has been opposed by marine mammal ENGOs on the grounds of operational noise from the wind turbines.

Humpback whales were removed from the Endangered Species Act threatened list in

2016 and their “unusual mortality event” has received less study and media coverage than NARWs.  They range between the Caribbean in the Winter to New England waters during the Summer. They feed on small forage fish (many of which are migrating up from the Mid-Atlantic region), while the sea herring population in the Gulf of Maine has collapsed (providing challenges for the lobster industry which uses them as bait).  Forage fish connect the phyto- and zooplankton to  fish; marine mammals and seabirds which are nearer the top of the food chain. The Northeast Fisheries Science Center’s EMaX (Energy Modeling and Analysis Exercise) examined the key role of forage species to the marine food chain on the Northeast Continental Shelf Ecosystem (which runs from Chesapeake Bay to the Maine/Maritime Province border).

Since both the predators and their prey have been shifting in space and time due to environmental stressors and a variety of human activities (US Navy Training; increased commercial ship traffic; nitrogen enrichment from coastal embayments and low dissolved oxygen levels in the bottom waters during the Summer; ocean acidity effects in the water column and in bottom sediments; etc.), this has changed the top down competition and predation in the marine food chain. I feel that the Atlantic Large Whale Take Reduction Plan scoping process should conduct a cumulative environmental impacts analysis as a contributing factor to the “UME" in NARW and  Gulf of Maine humpback populations throughout their range.

In addition, NOAA Fisheries GARFO issues incidental take permits for various human activities that impact endangered NARWs and I feel that these should be put on hold until the cause of the deaths exceeding the birth rates is determined and a solution is developed to solve this problem.  We don’t want humpback whales to return to the Endangered Species Act threatened list, so that incidental take  permits to allow human activities in the ocean should be more restrictive.  Most species under the ESA have their critical habitat listed and protected to aid in recovery plans.  The critical habitat should include the food chain for large whales and the related human endeavors and environmental stressors mentioned above.  There is a need to develop ecosystem-based management plans for large whale populations to aid in their management to address a shifting baseline in the ocean. 

The Take Reduction Plan

process for reducing deaths during "unusual mortality" events has to extend beyond those from fishing gear entanglements and include factors that influence the birth/growth/survival/health of these large whale species.  The present scoping process seems to be too simplistic to solve the challenges that we face from the consequences of “UMEs" in NARWs and humpbacks. I would urge folks that value these large whales in the ocean surrounding Cape Cod to take action to provide better protection of these beloved creatures which are important to our “Blue Economy” and attract many people to live on Cape Cod. I took a ship cruise the Gulf of Alaska in 2016 and one can see more large whales in the ocean regions adjacent to Cape Cod.

 

Dr. David D. Dow

East Falmouth, Ma.


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