Maycira Costa on board a boat on the B.C. coastline. (Maycira Costa)

1858 Naval maps combined with satellite data helps researchers map kelp bed health

UVic researchers have come up with a novel way of collecting data

A new tool for understanding kelp decline and its impact on B.C. coastal habitats has been developed by combining old naval charts with the latest satellite data.

Maycira Costa, a professor in the University of Victoria’s geography department, was in a colleague’s office when she noticed a beautiful old nautical chart on the wall from 1903.

“As I looked I saw drawings of plants on the coast. I have a separate satellite project and realized the areas on the map were the same as the satellite pictures.”

ALSO READ: Consultation process for marine conservation area on Vancouver Island continues after five years

The British Navy of the late 19th century was famous for its fastidious mapping, and they mapped kelp beds extensively as they presented a hazard to shipping. Costa realized the old maps were a potential gold mine of valuable data.

“I said, ‘Wow that’s amazing. Can we find maps for the whole Canadian coast?’”

Costa contacted the Canadian Hydrographic Service, who fortuitously had similar ideas, and were busy scanning and making digital copies of all the B.C. coastal charts they could find.

The process took several months, but at the end of it, the researchers were able to assess the accuracy of the maps.

They found that the maps were generally accurate and presented a viable baseline of data they could work from. Costa said modern biometric data shows that B.C. kelp beds run to a maximum depth of 30 metres. The British were known to get depth sounds and so when the researchers saw the British had noted kelp depths of 20 to 25 metres they knew the beds were likely to have been correctly recorded. Anything noted as deeper than 30 metres were not considered reliable.

ALSO READ: ‘Snow, melt, freeze, snow, melt, freeze’ leaves daffodils unpicked on the Peninsula

The researchers used British Admiralty charts from 1858 to 1956 and the maps were so accurate, later generations of maps built on the work of earlier cartographers and presented an accurate snapshot of kelp beds over the 100 year period.

Once the maps had been checked, modern satellite images of the same coastline were transposed over them, showing the differences in coastline and kelp beds.

Asked whether the maps hinted at any sunken treasure galleons, Costa laughed and said, “No sunken treasure ships but it was interesting as some features of the B.C. coastline didn’t match.”

She said that either there were errors during mapping or the maps could show sea level rises, erosion and sediment deposits over the generations. This is currently being studied.

ALSO READ: Groups target Health Canada approval of weed killer

The old nautical charts have proved especially helpful as they present an almost complete picture of kelp beds from their time, while there is currently no modern B.C. kelp bed map.

Costa has been part of a study that monitored kelp beds in Cowichan Bay from 2004 to 2017. During that time she has seen the kelp beds decrease and recover with fluctuating water temperatures. The new data, allied with this study should provide a more complete picture of a fragile ecosystem that is critical to species such as salmon and herring.

Costa said she enjoyed the novel way of collecting data, “We use high-tech satellites 700 kilometres above the earth’s surface, but then I get excited when I see the old historical charts and hold them in my hands.”



nick.murray@peninsulanewsreview.com

Like us on Facebook and follow us on Twitter

UVic

 

Some kelp underwater. Kelp forests are a critical ecosystem for herring and salmon. (UVic Geography department)

Just Posted

A video message from Mrime Minister Justin Trudeau was streamed to attendees at the State of the Island Economic Summit on Tuesday morning. (Vancouver Island Economic Alliance image)
Prime minister greets Vancouver Island economic summit attendees

Vancouver Island Economic Alliance conference being held virtually this week

Candice Woloshyn prepares her flower beds for the next season at her ‘Dirty Girl Flowers’ farm in Merville. Despite the pandemic, Woloshyn was able to sustain her homegrown business as community members opted for regular deliveries of fresh cut flowers. Photo by Binny Paul/ Campbell River Mirror.
Vancouver Island flower farmers were blooming as the pandemic wilted everything else

Floriculturists saw increased subscriptions as fresh flowers became a ‘sight for sore eyes’ during isolation

Struggling to afford rent, Sylvia Bailey is hoping to trade her love of cooking for some more affordable accommodation. (Photo courtesy of Sylvia Bailey)
Retired Victoria woman looking to cook, clean or garden in exchange for rent

Sylvia Bailey is hoping to use her love for cooking to help afford rent

View Royal Coun. John Rogers stands next to an unearthed home heating oil tank. As a way to prevent environmental disasters, he is lobbying for a provincial registration system and mandatory inspection for all above-ground tanks, as well as a requirement to remove any underground tanks not used for a prescribed period of time. (Don Descoteau/News Staff)
Efforts to regulate Greater Victoria home heating oil tanks continues

View Royal councillor part of movement to identify old tanks, prevent catastrophic leaks

International Bat Week (Oct. 24-31) is a time for people to learn more about the nocturnal creatures and how to protect them. (Photo by Cory Olson)
Holy Halloween, it’s Bat Week!

Bats have been getting a bad rap — B.C. Bat Program looks to change that

Carolyn and Steve Touhey came across a pod of humpback whales while on their boat Sunday, Oct. 25. Photo supplied
VIDEO: Boaters encounter pod of humpbacks in Georgia Strait

Pod spotted between Comox and Texada Island

Prime Minister Justin Trudeau provides an update on the COVID pandemic during a press conference in Ottawa on Tuesday, Oct. 27, 2020. THE CANADIAN PRESS/Sean Kilpatrick
Trudeau says pandemic ‘really sucks,’ and that Christmas gatherings are up in the air

The prime minister encouraged residents to continue to follow the advice of local health authorities

The Williams Lake Indian Band is stipulating no-go zones for mushroom picking in areas burned by last summer’s wildfires. 100 Mile Free Press photo
Who controls mushroom harvesting on Indigenous lands?

‘We don’t necessarily know where the mushrooms grow, how old the stands need to be, those types of things.’

Canadian and American flags fly near the Ambassador Bridge at the Canada/USA border crossing in Windsor, Ont. on Saturday, March 21, 2020. THE CANADIAN PRESS/Rob Gurdebeke
U.S. election results one factor that could impact immigration to Canada next year

The survey polled 1,523 Canadians between Oct. 23 and Oct. 25

The voting station mimicked a real voting station in Nicole Choi’s classroom at Chilliwack middle school on Oct. 22, 2020, where students had to show their ID (student cards), be checked off a list, and mark a secret ballot behind a screen. (Jessica Peters/ Chilliwack Progress)
B.C. students choose NDP majority in mock election

More than 90,000 youth took part in school-based election process

Crew transport bus at the Trans Mountain pipeline project work site in Burnaby, March 2020. (Trans Mountain)
Check your workplace COVID-19 safety plans, Dr. Henry urges

Masks in public spaces, distance in lunchrooms for winter

Kelowna City Hall has been vandalized overnight. (Michael Rodriguez - Capital News)
Kelowna City Hall hit by anti-pandemic vandalism

Graffiti condemning the virus appears overnight on City Hall

FILE – A woman smokes a marijuana joint at a “Wake and Bake” legalized marijuana event in Toronto on October 17, 2018. THE CANADIAN PRESS/Christopher Katsarov
Home nurse visits could play big role in reducing cannabis use, smoking in young mothers

The program, dubbed the BC Healthy Connections Project, involves public health nursing home visits

Emergency crews respond to an apartment fire on Tuesday, Oct. 20. (PHOTO COURTESY JERRY FEVENS)
Port Alberni RCMP investigate possible arson

Fire was contained but three people displaced in aftermath

Most Read