VIRGINIA BEACH — A juvenile humpback whale washed ashore in Virginia Beach Sunday, the third in less than two weeks.
Mendy Garron, the greater Atlantic region marine mammal response coordinator for the National Marine Fishery Service, said the recent amount of strandings is unusual, but that there is no definitive answer why. Southside Daily interviewed Garron in an attempt to get closer to one.
Is the number of unusual humpback whale strandings in the area specific to Virginia Beach?
“We will typically see humpback strandings this time of year in the mid-Atlantic area, because over the last couple years we’re seeing an increase of juvenile animals, kind of ‘over-wintering’ in that area. They’re there for food. But we have seen three cases within a 10-day period, and that’s pretty unusual for this time of year. They tend to be a little bit more spaced out temporally, over the winter months.”
Whales use sound to navigate. Do you know if the recent strandings are related to sonar used by the military?
“We have no evidence that would indicate that that is a factor. It’s definitely something that is taken into consideration for stranding response, and when we’re doing investigations for stranding cases.
A necropsy examination really looks in depth at the animal’s internal organs. We take significant samples when we’re able to, and we do a large variety of analysis. So we see if there’s any disease or lesions. If it indicates there is any type of disease, we’ll send samples off to be tested for viruses and bacteria.
Then there are specific signs in different species that can indicate some hearing loss. It’s really kind of detective work, looking at each case, and what it’s presenting you with to go down a path.”
Can the increase in humpback whales be the reason for the recent strandings?
“What we typically see in wild populations is as populations increase, there will be an increase in natural mortality. So for some of the younger animals, like yearlings or juveniles, we do see a higher rate of mortality in those animals, because they’re not learning to fend for themselves or thriving on their own. That’s natural.
But what we’re seeing here, or what we think we’re seeing here, is that as the population increases, there are more animals that are younger in age, over the last couple of years, that are residing in that mid-Atlantic area. That leads to some risks, especially in a high traffic area such as Virginia. They are in areas that overlap with vessels. So that does make them susceptible to vessel collisions.”
Why do whales get so close to the coast?
“Their normal feeding ground is up in the New England area. So we typically see them up in New England waters during the summer months. Then, over the fall and winter, they will migrate down south, it’s a breeding area near the Caribbean islands. What we do see now are these juvenile animals that are not sexually mature hanging out off the mid-Atlantic area and just feed during that breeding time. So they’re not expending all of their energy to go down to the mating areas. So they’ll stay here for food, to get fattened up.
Whales have an internal migratory behavioral system. Their migratory patterns are very well established from birth, so they tend to go to the same feeding areas that their mothers took them. So we do see these juvenile animals that tend to either stray from that normal migratory pattern. Sometimes the juvenile animals will find an unusual area, they like to follow food. We’ve seen them in shallow harbors or up rivers sometimes.
It’s just a part of their biology, learning to fend for themselves and learning to feed on their own. But then typically they get back in their groove and will continue down that migratory path, and then as they become sexually mature, they follow the full migratory path down south and back up to the north.”
NASA is investigating solar storms and its possible affect on mass strandings. What do you think about this theory?
“I don’t know specifically about the NASA project, but that’s also been kind of a theory over the years if there’s a correlation between mass stranding events and solar patterns and lunar patterns. We typically see some mass strandings coming in on some super high tides that are associated with full moons. It’s kind of a long-standing question. I think any results out of that type of investigation would be really interesting.”
Is there a common theme surrounding the recent whale strandings in Virgnia?
“For the cases Virginia has examined, one interesting finding has been their full stomachs. So it’s very evident these animals are actively feeding in the area, and they’re probably following food closer to shore.
Over the last several months, up along the coast up to New York and New Jersey, we’re seeing humpback whales very close to shore following prey. So when those animals are actively feeding, they become very vulnerable. That’s really the only thing they’re paying attention to. So they aren’t paying attention to a vessel that’s coming their way.”
Why does the necropsy process take months to complete?
“Marine mammals do present different challenges, I think, than other wildlife species because they have a very thick layer of blubber. So what often happens is when they expire, the body heat is kept within that blubber. So a lot of the tissues and muscles tend to degrade really really quickly. So getting viable samples for a lot of this testing can be very challenging when you’re dealing with these cases.
We try to get as much as we can, and learn as much as we can from each case, but we’re not getting the same samples from each case to have a complete story. Across the country, our national network responds to thousands and thousands of cases on an annual basis, and we have a few select labs that specialize in marine mammal tissue analysis.
So that can make it challenging. Some of our samples might be sent off to California for analysis, where they’re getting samples from across the country. So they might have an order in which they are processed. But they’re experts in their field, so that’s why we do it that way.”
What are next steps in controlling this stranding situation?
“So in cases like this, there are some things that we can do to see if there’s anything going on in the environment that might be contributing to these strandings. Part of that is looking at the shipping activity that’s in the area. We do have some shipping speed rules that are in place, and just making sure folks are complying with them.
On the bigger scale, we do have a program for unusual mortality events with the marine mammal health program. So when we do see cases that are beyond the normal trend in standings, we work with an external group of experts that review the data, and there are certain criteria that may be met to designate it as an official unusual mortality event.
When that happens, it becomes more or less a federal investigation. So we have the ability to open up some additional resources at the federal level to help with these types of investigations and to standardize our analysis to see if it can better inform us on what is causing these events to happen.”
Would the recent stranding events in the area meet that criteria?
“It’s definitely unusual for this area. But we have been monitoring humpback whale strandings over the last year, and we’ve been a little above normal for our annual trend we typically see across the region. With the increase in whale population, we do expect to see a little bit of an increase.
We’re just kind of monitoring it right now across the region. And now as the migrate down south, that will expand into our south east region. So we’re coordinating very close with them, just to keep an eye on the stranding numbers for humpbacks.”
Follow Justin on Twitter @justinbmmj and contact him at justin@wydaily.com
