麻豆传媒

 

Citizen science helps detects sharks earlier

- July 26, 2018

A great white shark. (Provided photos)
A great white shark. (Provided photos)

When Darren Porter obtained his commercial weir license eight years ago and set up shop in Bramber, Nova Scotia, he never thought he鈥檇 be at the centre of an international shark-tracking effort.

The 麻豆传媒-based (OTN) has been linking up the Bay of Fundy and surrounding inland waters with monitoring devices to track commercially and ecologically valuable marine species. Porter鈥檚 weir is a perfect monitoring spot to help capture the migrations of fishes like American shad, skates, and striped bass, tracking them as they travel throughout the Basin and beyond.

As the tides in the Bay of Fundy ebb in and out from the shoreline, a V-shaped net traps fish and other marine animals and allows fishers to harvest only what they need.


Darren Porter鈥檚 commercial fishing weir in Bramber, Nova Scotia, is built and torn down each year from March to April during low tide.

鈥淲e have different ponds set up to hold things in that we don鈥檛 commercially use, when the tide comes back in, it just lifts to fish up and they move away. I harvest only a little piece of each tide.鈥

For the last two years, Porter has looked after a key acoustic telemetry monitoring infrastructure in the Minas Basin. He works with OTN researchers at Acadia University studying sturgeon in particular 鈥 a critically endangered species, and the source of precious and expensive caviar. Tidal turbine developments scheduled for Fundy region may impact sturgeons鈥 movements and survival. But lately, Porter鈥檚 focused on another animal moving through his waters, (though not in his weir): white sharks.

Tracking Anadale


Andale is a white shark acoustically tagged by Greg Skomal and John Chisholm at the Massachusetts Shark Research Program (MSRP) in 2012. She has been documented going back and forth between southern Atlantic U.S. and Canada, including Nova Scotia鈥檚 southwestern shores into the Bay of Fundy, for six years.

She was detected just off Cape Split, Nova Scotia, a popular hiking area and home to seal hangouts.

(Image right: Acoustic receiver monitoring coverage in the Minas Passage/Bay of Fundy.)

While the appearance of white sharks on North America鈥檚 east coast has caused a stir among beach-goers, both fishers and scientists maintain that the animals have always moved through these waters.

鈥淚ts all about basic needs,鈥 says Fred Whoriskey, executive director of OTN. 鈥淭he Atlantic region, including Cape Cod up to Newfoundland, has seal colonies 鈥 sharks are just following the food.鈥澛

The power of collaboration


For the last few years, Porter鈥檚 found himself in a unique position as a citizen scientist. Not only does he help maintain the existing OTN monitoring system, he鈥檚 added to it by buying and deploying his own gear (funded through Big Moon Power) to track species important to his own livelihood.

鈥淚 can access places cheaper, faster and more efficiently than anybody else because I already have the gear and my life already revolves around nature,鈥 he says.

Porter regularly checks in with OTN and MSRP on white shark detections in the area. He hopes the public perception of sharks will change and marine animals can be seen as more than just resources. 鈥淲e have to have more outreach, we must educate the public on what鈥檚 here.鈥

He also strongly advocates for the integration of local and traditional (First Nations) knowledge when it comes to designing research studies. 鈥淵ou need a basic understanding prior to the commencement of any scientific operation,鈥 explains Porter. 鈥淲e fish 14 tides a week for 299 tides straight; every single fish counted measured and recorded. That鈥檚 never been done before and that鈥檚 what we need: fishermen, Indigenous knowledge and traditional uses.鈥

Research through partnership


Last year, the OTN Minas Basin receivers picked up Pumpkin, another white shark tagged by the Massachusetts team. The news generated significant buzz for being one of the earliest white shark detections in this area ever recorded and, fittingly, was detected near Windsor, Nova Scotia 鈥 known as the pumpkin capital of the world.


Pumpkin, an acoustically tagged white shark, made an appearance last year in Minas Basin, Nova Scotia.

鈥淚鈥檝e seen sharks out my backdoor for many years but not everyone believed me. Now she鈥檚 鈥榬eal鈥 because she鈥檚 been detected with acoustic receivers. Pumpkin was a great way to bring people closer to the value of local knowledge holders.鈥 Pumpkin was detected in Cape Cod on July 17.

Andale will be monitored by roughly 80 receivers in the Minas Passage while she鈥檚 here and is expected to move off when waters begin to get colder in late summer/early fall, or when food becomes scarce. Porter continues to offload receivers in Minas Passage weekly, sometimes daily, and connects with OTN and MSRP scientists adding significant capacity to the research.

鈥淭his is a story of partnership, transparency and technology: you have the U.S. and Canada working together, fishermen working with scientists, and different technologies and uses coming together,鈥 says Porter. 鈥淚f you can partner with all the stakeholders, you bring us all to the table, you take the skill sets of everyone involved, we can achieve second-to-none science.鈥

Porter鈥檚 fishing weir was recently the subject of a short film documenting such partnerships. .