#3: Where are the right whales?

We had another good survey day yesterday- great visibility and calm seas- and found no right whales. The arrival date for right whales in the Bay of Fundy has changed quite a bit from past years to more recent years. In the 1990's, they frequently arrived in early July. In the 2000's, they reverted to what we think of as their usual pattern of arrival- early August, with a few appearing in late June or July. Even though we know the arrival date will vary, whenever we find few to no whales, we begin to wonder: Why aren't they in the Bay? If they're not in the Bay, then where are they?

File photo: Kelsey Howe, taken on last day of BOF 2011 surveys.

One thought about the first question is that the sea surface temperature has been quite a bit warmer this year- 58-59 degrees F compared to the more usual 46-52 degrees F. The plankton that right whales depend upon require specific conditions that may well have changed. Also, a recent study discovered dramatic reductions in phytoplankton in the Gulf of Maine in recent years. Phytoplankton, or plant plankton, is the very base of the food chain and is dinner for the copepods that right whales feed on. So with warmer water temperatures and reduced volume of phytoplankton, it's possible that there's been some shifts in the food resource for right whales- perhaps the copepods are available in a different location than usual, or at a slightly different time of year.

Assuming that right whales are responding to these or other environmental variations, changes in their distributions may actually be a positive sign. It may be demonstrating their ability to adapt to what will likely be an increasingly changing environment. While some people still try to deny the evidence of climate change, animals around the world are already highlighting the environmental changes by altering their normal ranges--from birds and butterflies to whales. For example, are the conditions that have made the Bay of Fundy favorable to sperm whales in the last three years unfavorable for right whales?

As to the second question of where the right whales may be, there are several possibilities. The NOAA's Northeast Fisheries Science Center's aerial surveys in July had right whales on the northen edge of George's Bank and near Cashes Ledge- all south of the Bay of Fundy (see map from their interactive web site below).

There have been no recent surveys in those areas, so it is unknown if they are still there. We have also received several reports of right whales in the Gulf of St. Lawrence this summer--an area that seems to be important to some right whales but which has not been well surveyed. It's a big ocean and there are many other places that right whales could be. We hope that many will make their way to the Bay of Fundy soon, but wherever they are, we hope they are finding all the copepods they can eat!

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