Sharks, Seals, and a Healthy Ocean Ecosystem

 

Brian Yurasits | Marine Mammal Rescue Community Outreach Manager

Photograph by Gerald Chombs

This week Maine experienced its first-ever fatal great white shark attack, leaving many New England residents shocked and in search of answers. While we aren’t shark experts here at Seacoast Science Center, our Marine Mammal Rescue Team offers unique insight into the complicated dance between predator and prey in the Gulf of Maine. 

According to shark researcher Greg Skomal, attacks like this are extremely rare, and most likely cases of mistaken identity. White sharks are ambush hunters who target seals, a prey item that looks similar to a swimmer wearing a wetsuit. 

Great white sharks have historically occurred in waters from Nova Scotia to New Jersey during the Summer months. Their presence here isn’t something new, and so a warming Gulf of Maine is not necessarily the reason we are noticing great whites venturing North. 

Since the 1970’s, populations of marine mammals, sharks, and other fish have all generally benefited from protections put in place in response to unrestrained harvest, bounty hunting (in the case of seals), and pollution that have led to the disruption of the Gulf of Maine’s marine ecosystem. 

As some managed elements of the Gulf of Maine’s marine ecosystem return to a more ‘natural’ state, it’s inevitable that we will see examples of species interactions that appear to be new from a short term frame of reference but are in fact natural and historic.  Great white sharks hunting seals along the coast is one such example. With increased interactions between people and sharks, it’s crucial that we learn more about these iconic marine animals.  Knowledge is the key to co-existing with the marine environment and increased understanding is fundamental to reducing the risk of tragic interactions between sharks and people recreating in the ocean environment. 

How To Stay Shark-Smart This Summer

To keep you safe while recrecreating in the Gulf of Maine we urge you to become familiar with the public safety recommendations of  the Atlantic White Shark Conservancy

  • Be aware sharks hunt for seals in shallow water.  
  • Stay close to shore where rescuers can reach you.
  • Swim, paddle, kayak and surf in groups – don’t isolate yourself.
  • Avoid areas where seals are present.
  • Avoid areas where schools of fish are visible.
  • Avoid murky or low visibility water.
  • Limit splashing.
  • Adhere to all signage and flag warnings at beaches.
  • Follow instructions of the lifeguards.
  • Download the Sharktivity App 

Seacoast Science Center Marine Mammal Response in New Hampshire and Northern Massachusetts

Seacoast Science Center’s Marine Mammal Rescue Program works as a part of the Greater Atlantic Marine Mammal Stranding Network, responding to incidents of seals and other marine mammals from Essex, MA to Maine’s southern border. 

Our team collects data on these animals to help us better understand how seal populations are changing in the Gulf of Maine. Our work contributes to the scientific process that identifies and manages threats to marine mammal populations. SSC has recorded 8 suspected or confirmed shark predations on seals in our response territory since 2014. However the vast majority of observed seal mortalities are related to disease, infections, and juvenile abandonment.

Brian Yurasits and Ashley Stokes, Marine Mammal Rescue Manager

References

https://www.fisheries.noaa.gov/resource/document/magnuson-stevens-fishery-conservation-and-management-act

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0099240

https://www.fisheries.noaa.gov/new-england-mid-atlantic/marine-life-distress/2018-2020-pinniped-unusual-mortality-event-along

https://nefsc.noaa.gov/program_review/2015-review/BACKGROUND/B2C5Waring%20bounties.pdf

https://academic.oup.com/bioscience/article/67/8/760/3865418

http://nasrc.whoi.edu/faqs

https://www.nationalgeographic.com/animals/2020/07/maine-shark-attack-public-safety-issue-conservation-success/

https://www.fisheries.noaa.gov/species/north-atlantic-right-whale#:~:text=Entanglement%20in%20fishing%20gear%20and,and%20is%20also%20a%20concern.

 

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