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Mark Mattson

@waterkeepermark.bsky.social
1.6K followers 1.2K following 463 posts

President Swim Drink Fish. Former Lake Ontario Waterkeeper. Lives in Great Lakes St Lawrence River watershed. Biinaagami

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Mark Mattson @waterkeepermark.bsky.social · 28/09/2026
Once people swim - they become fierce protectors. Great piece from @cangeo on how the Swimmable Cities movement is taking root across the Great Lakes, from Kingston's Gord Downie Pier to the sunrise swimmers in Oakville. Is your waterfront swimmable? canadiangeographic.ca/articles/mak...
canadiangeographic.ca
Making swimmable cities in the Great Lakes watershed
How three organizations have come together to promote urban swimmability and change our relationship with water — one plaque at a time
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Mark Mattson @waterkeepermark.bsky.social · 23/09/2026
"Swimmers are evidence of communities rebuilding their relationships to water." From Kingston's Gord Edgar Downie Pier to North Van and now Kelowna, how creating safe public swimming is inspiring the next generation to protect our waters. waterkeepermark.substack.com/p/canadians-...
waterkeepermark.substack.com
Canadians Moving Forward With Third  Swimmable Pier
Kelowna British Columbia
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Mark Mattson @waterkeepermark.bsky.social · 20/09/2026
Last day of summer. Still time for a few more swims. Looking to the fall with lots of new roads ahead. Change is always good. Although I will miss the summer and happily welcome it back in 9 months.
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Mark Mattson @waterkeepermark.bsky.social · 18/09/2026
So grateful to the Waterkeeper Alliance for the Terry Backer Award. waterkeepermark.substack.com/p/on-receivi...
waterkeepermark.substack.com
On Receiving the Waterkeeper Alliance Terry Backer Award
I was in Ecuador this week, in spirit.
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Mark Mattson @waterkeepermark.bsky.social · 18/09/2026
Thinking of all the Waterkeepers from around world in Ecuador this week. So exciting. Miss the friendship and inspiration. Best to everyone. @Waterkeeper
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Mark Mattson @waterkeepermark.bsky.social · 18/09/2026
Ottawa spends millions on D.C. networking trips while a 200 year old cross-border crossing between Cape Vincent & Wolfe Island hangs by a thread despite U.S. efforts to save it. The Horne’s Ferry, a chance for Canada to step up. waterkeepermark.substack.com/p/an-opportu...
waterkeepermark.substack.com
An Opportunity on Wolfe Island for Canada to Support Our New York Neighbours
The Horne’s Ferry Is About More Than A Border Crossing
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Mark Mattson @waterkeepermark.bsky.social · 17/09/2026
Wolfe Island has so many roads leading from highway down to Lake Ontario or St Lawrence River. Privileged to have reason to follow the paths to homes & meet Island community. Every discussion touches on emergency services & reliable ferry access to Kingston.
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Mark Mattson @waterkeepermark.bsky.social · 16/09/2026
Out and about on Wolfe Island. Grateful for support.
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Mark Mattson @waterkeepermark.bsky.social · 11/09/2026
Was on Wolfe Island Sept 11 2001 & heard from friend in New York about the attacks on US and the towers. Over next 12 hrs Canada took in 33,000 passengers & crew aboard 225 diverted flights from US into Canada. We were family that day.
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Mark Mattson @waterkeepermark.bsky.social · 10/09/2026
Hundreds of thousands of people each week move under 100km between Toronto Hamilton and Kitchener Waterloo and it takes 2 hours. A 30-minute high-speed rail corridor would be Canada’s biggest nation builder connecting millions. substack.com/@waterkeeper...
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Mark Mattson @waterkeepermark.bsky.social · 10/09/2026
Money can't build a country by itself. At this week's Toronto investment summit, it'll take trade, trust and talent, not just speed, to get nation building right. Also .. my ideas for great projects to pitch for Canada and Ontario. waterkeepermark.substack.com/p/what-natio...
waterkeepermark.substack.com
What Nation-Building Is All About
Advice to Team Canada and Investors at the Toronto Summit
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Mark Mattson @waterkeepermark.bsky.social · 07/09/2026
Wolfe Island is the Heart of Lake Ontario. Will be good for upstate New York and Eastern Ontario when the Horne’s Ferry begins to connect our communities again. Great to see so many good people trying to make it happen.
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Mark Mattson @waterkeepermark.bsky.social · 06/09/2026
Horne’s Ferry returning to Horne’s Point is a great sign. The crossing at the end of Lake Ontario between Wolfe Island & Cape Vincent NY has been going on for decades & underscores strong relationship between upstate NY & Ontario. Hope customs offices return soon.
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Mark Mattson @waterkeepermark.bsky.social · 04/09/2026
Lake Ontario doesn’t recognize borders, executive orders or political slogans. The Great Lakes St. Lawrence watershed belongs to no one. It’s something we share and have a shared responsibility to protect. Check out Biinaagami.ca waterkeepermark.substack.com/p/biinaagami...
waterkeepermark.substack.com
Biinaagami: The Shared Story Of Lake Ontario, The Great Lakes and The St Lawrence Watershed
(Photo: Patrick Madahbee, Meredith Brown, and Mark Mattson standing on their shores: exploring the Great Lakes St.
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Mark Mattson @waterkeepermark.bsky.social · 01/09/2026
Official signs are hitting the ground across Wolfe Island. 💙 Proud to stand for Ward 1 Councillor and work together for future of Islands, the true heart of Lake Ontario and the St. Lawrence River. Want a sign for your lawn?
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Mark Mattson @waterkeepermark.bsky.social · 30/08/2026
For 117 years, the International Joint Commission has kept Canada and the U.S. working together on shared waters. Through wars, trade fights and pollution. Now Lake Ontario is a test of whether that cooperation still holds. waterkeepermark.substack.com/p/lake-ontar...?
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Mark Mattson @waterkeepermark.bsky.social · 29/08/2026
No one is getting ripped off. The real question isn’t whether the US needs Canada, it’s whether either country still wants what we’ve built together. waterkeepermark.substack.com/p/lake-ontar...
waterkeepermark.substack.com
Lake Ontario In The Spotlight For All The Wrong Reasons
Binational Disagreement Over Name Of Lake Ontario Threatens Cooperation on Great Lakes
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Mark Mattson @waterkeepermark.bsky.social · 25/08/2026
Lake Ontario Deserves More From President Trump. Water has the power to unite people, to make them stronger, to build futures. Lake Ontario is Beautiful Water. waterkeepermark.substack.com/p/lake-ontar...
waterkeepermark.substack.com
Lake Ontario Deserves More From The President
There's going to be plenty said about whether President Trump has the power and support to rename Lake Ontario.
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Mark Mattson @waterkeepermark.bsky.social · 25/08/2026
Is Lake America the moment the Trump presidency jumped the Lake Ontario shark. @waterkeeper Not very respectful of a name that means beautiful waters or a watershed that is a shared responsibility. Lake Ontario existed long before America will survive this insult as well.
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Mark Mattson @waterkeepermark.bsky.social · 20/08/2026
10 years ago today, The Tragically Hip played their last show in Kingston. I still think about Gord and what he taught me. On gratitude, the Lafarge case and the work that doesn’t stop. waterkeepermark.substack.com/p/grateful-t... @Waterkeeper
waterkeepermark.substack.com
Grateful: Ten Years After the Last Show, Remembering Gord Downie
Ten years ago today, The Tragically Hip played their last show at the K-Rock Centre in Kingston.
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Mark Mattson @waterkeepermark.bsky.social · 18/08/2026
Jack Nicklaus learned to hunt ducks with his Uncle on Wolfe Island and named it a place he goes when not golfing. What makes Wolfe Island worth supporting: the ferries, the emergency access, the way of life people love like something you earn. waterkeepermark.substack.com/p/wolfe-isla...
waterkeepermark.substack.com
Wolfe Island: Somewhere Worth Talking About
Love it the way you love something you earned
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Mark Mattson @waterkeepermark.bsky.social · 12/08/2026
Deep roots, new chapter. I’m officially running for Council on Wolfe Island! I look forward to working to address the Island transportation, safety and sustainability. Read my full announcement here open.substack.com/pub/waterkee...
open.substack.com
Running for Council on Wolfe Island.
Ontario Municipal Elections: October 26th 2026
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Mark Mattson @waterkeepermark.bsky.social · 05/08/2026
Swimmable water is a revelation. open.substack.com/pub/waterkee...
open.substack.com
Swimming is a Revelation
Why August Belongs to the Canadian Swimmer
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Mark Mattson @waterkeepermark.bsky.social · 29/07/2026
87,000 people just told Ottawa to stop dumping fill in Toronto Harbour. Now comes the real test: the Canada Ontario Great Lakes Agreement. 55 years and still unfinished business. open.substack.com/pub/waterkee...
open.substack.com
Ten Agreements Over 50 Years. The Great Lakes/St. Lawrence River Watershed is Still Waiting for Canada and Ontario to Finish the Job
Did Billy Bishop Decision Change the Momentum?
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Mark Mattson @waterkeepermark.bsky.social · 27/07/2026
Engineers once called Toronto Harbour beyond saving. Now, fed gov kills idea for filling in Lake for Billy Bishop & City opens 10 acres of Biidaasige Park. The harbour didn’t get saved by engineers, it was saved by people who kept showing up for it. open.substack.com/pub/waterkee...
open.substack.com
The Toronto Harbour Shines
Biidaasige Park and Billy Bishop
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Mark Mattson @waterkeepermark.bsky.social · 25/07/2026
The Toronto Harbour Shines. Biidaasige Park and Billy Bishop open.substack.com/pub/waterkee...
open.substack.com
The Toronto Harbour Shines
Biidaasige Park and Billy Bishop
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Mark Mattson @waterkeepermark.bsky.social · 24/07/2026
Good show on swimmable water and cities in Canada this morning on The Current. Use @swimguide to find beaches and clean water before you swim. www.cbc.ca/listen/live-...
cbc.ca
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Mark Mattson @waterkeepermark.bsky.social · 24/07/2026
Today, federal comment ends for proposal to fill in Harbour & Lake to extend Billy Bishop runway. Message from public consultation is that Toronto Harbour, the water park, has emerged as powerful new voice for restoration and protection of Lake Ontario. open.substack.com/pub/waterkee...
open.substack.com
The Toronto Harbour Dream
If you get a chance this summer, go down to the Toronto waterfront.
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Mark Mattson @waterkeepermark.bsky.social · 23/07/2026
The Toronto Harbour Dream. What if the heart of Toronto’s waterfront wasn’t meant to be like this? open.substack.com/pub/waterkee...
open.substack.com
The Toronto Harbour Dream
If you get a chance this summer, go down to the Toronto waterfront.
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Mark Mattson @waterkeepermark.bsky.social · 22/07/2026
Rosy Fingered Dawn boat ride with my friend Murray. Murray helped me become the Lake Ontario Waterkeeper back in 2001. Always great to get together - talk water, trees, family. Eat pizza.
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Mark Mattson @waterkeepermark.bsky.social · 21/07/2026
We're Hiring: The Next Chief Executive Officer and President of Swim Drink Fish Why this is the most exciting environmental leadership opportunity in Canada right now open.substack.com/pub/waterkee...
open.substack.com
We're Hiring: The Next Chief Executive Officer and President of Swim Drink Fish
Why this is the most exciting environmental leadership opportunity in Canada right now
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Mark Mattson @waterkeepermark.bsky.social · 20/07/2026
Just watching the world sail by today. Lots to write about and calls to follow up on but it will have to wait until the rain tomorrow.
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Mark Mattson @waterkeepermark.bsky.social · 19/07/2026
Just an fyi — if the Lake Ontario Blue Jays get Bo Bichette back from Mets — I will be invested in the next 70 games like, for real. Truth is, coming home for home, is what’s it’s all about. #odyssey
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Mark Mattson @waterkeepermark.bsky.social · 17/07/2026
As we finalize comments on the proposal to expand runway in Toronto to allow for jets and more traffic (due July 24th) … good to remember that this project will make things worse for water quality by trapping contaminated water longer in harbour. Primer here. youtu.be/PTMoJafcwlQ
youtu.be
Toronto Harbour Report 2016
YouTube video by LOWaterkeeper
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Mark Mattson @waterkeepermark.bsky.social · 15/07/2026
Toronto Harbour isn't finished being restored. We can't give up on it now. On the Great Lakes, Billy Bishop & why we shouldn't accept a degraded baseline as the status quo open.substack.com/pub/waterkee...
open.substack.com
Toronto Harbour Isn't Finished Being Restored. Don't Give Up Now.
How a decades old commitment to the Great Lakes is being quietly bypassed and why the debate over Billy Bishop Airport is about much more than a runway.
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Mark Mattson @waterkeepermark.bsky.social · 12/07/2026
7 things Toronto needs before we talk about expanding into the harbour: real-time CSO monitoring, debris cleanup, swimmable access in the West End, not a Special Economic Zone that waives the rules.
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Mark Mattson @waterkeepermark.bsky.social · 12/07/2026
That murky plume in Toronto Harbour isn’t an accident, it’s 9 sewer outfalls plus the Don River. It already struggles to flush. A new report shows a Billy Bishop runway expansion would cut harbour flow in half. Time for a public summit on this waterfront. open.substack.com/pub/waterkee...
open.substack.com
What Is Guarding the Water Around Billy Bishop Airport Toronto and in Ontario?
Toronto's Inner Harbour where the Don River and combined sewer outfalls meet the bay.
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Mark Mattson @waterkeepermark.bsky.social · 11/07/2026
New city report: expanding Billy Bishop’s runway could cut water flow through Toronto’s Inner Harbour by 50%, trapping sewage and pollutants twice as long & undo billions spent cleaning up the harbour. “It’s reckless,” www.cbc.ca/news/canada/...
cbc.ca
Expanding Billy Bishop runway could degrade Toronto harbour water quality, city report says | CBC News
A new city report says the province's plan to expand the runway at Billy Bishop airport to accommodate jets could reduce water flow in Toronto's Inner Harbour, limiting its ability to flush sewage and...
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Mark Mattson @waterkeepermark.bsky.social · 10/07/2026
Funny way of saying swimmable drinkable fishable harbours are valuable assets to cities & business. But yes, “we know knowledge workers value urban amenities and access to nature. If our waterfront becomes less attractive, Toronto becomes less attractive to knowledge workers.”
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Mark Mattson @waterkeepermark.bsky.social · 10/07/2026
Summers are a great time to celebrate birthdays. Happy birthday to my sister Kris who is always there for her family when it counts and when no one notices.
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Mark Mattson @waterkeepermark.bsky.social · 07/07/2026
Over 5000 views for this substack rebuttal. Why? B/c the @globeandmail left out discussing the lake & waterfront in Billy Bishop editorial. I didn’t. Still a governing agreement that prohibits filling Lake. Public comment closing July 24. open.substack.com/pub/waterkee...
open.substack.com
What the Globe Left Out: Billy Bishop, the Harbour and Toronto's Waterfront Future
How to Win an Argument Without Having It
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Mark Mattson @waterkeepermark.bsky.social · 06/07/2026
The Globe’s Billy Bishop editorial reduced Toronto’s harbour to “some impact on boats.” No one has published how much lake gets filled in, so I did the math & came up with 60,000 truckloads for a project currently illegal under its own governing agreement open.substack.com/pub/waterkee...
open.substack.com
What the Globe Left Out: Billy Bishop, the Harbour and Toronto's Waterfront Future
How to Win an Argument Without Having It
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Mark Mattson @waterkeepermark.bsky.social · 01/07/2026
Second Greatest Blessing: A Note on Canada Day open.substack.com/pub/waterkee...
open.substack.com
Second Greatest Blessing: A Note on Canada Day
5 Things Worth Celebrating
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Mark Mattson @waterkeepermark.bsky.social · 30/06/2026
A 2003 EA said Billy Bishop’s habitat was already degraded so new damage didn’t count. Now a runway extension into Lake Ontario & new nuclear reactors proposed on its shores. A degraded baseline is not permission. 9 million people drink this water. open.substack.com/pub/waterkee...
open.substack.com
Nine Million People Drink This Water
A Lake Worth Talking About
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Mark Mattson @waterkeepermark.bsky.social · 25/06/2026
After 25 years as President of Swim Drink Fish I am moving to the board. New essay on what running a charity actually demands and why the oath is the whole thing. open.substack.com/pub/waterkee...
open.substack.com
What Makes Running a Charity Special: A View from the Water’s Edge
There is a type of work that not many want to do.
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Mark Mattson @waterkeepermark.bsky.social · 21/06/2026
Today is National Indigenous Peoples Day. Our Biinaagami work exists because of the Shared Circle of Knowledge Keepers. Grateful for these partnerships. #biinaagami
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Mark Mattson @waterkeepermark.bsky.social · 19/06/2026
“The entire habitat is degraded, therefore none of the impacts are considered significant.”That’s the actual line from a 2003 government report on Toronto’s harbour. It’s the hidden argument behind every push to fill in more of Lake Ontario. #biilybishop open.substack.com/pub/waterkee...
open.substack.com
Toronto’s Waterfront Is Not a Runway — It’s an Inheritance Worth Building
What fifty years of harbour cleanup proved — and why July 24 is our next chance to prove it again.
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Mark Mattson @waterkeepermark.bsky.social · 18/06/2026
With today’s rain comes inevitable: sewage bypasses at treatment plants & 92 lesser-known combined sewer overflow along Toronto’s rivers & waterfront discharging untreated sewage directly into Lake. The city will notify you. They just won’t tell you what it means. open.substack.com/pub/waterkee...
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Mark Mattson @waterkeepermark.bsky.social · 18/06/2026
Ontario spent $9.93M on push to Protect Ontario ads hyping nuclear energy. Without independent, fact-based investigation into the real consequences, this isn't public education—it's just government propaganda. www.thetrillium.ca/news/politic...
thetrillium.ca
‘Protect Ontario’ ads cost one ministry nearly $10M last year: records
Ontario taxpayers were on the hook for millions last year to watch the provincial government promote its own initiatives
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Reposted by Mark Mattson
Les Holt @lesholt.bsky.social · 16/06/2026
“. . .five questions matter: Does it address the legacy of past pollution? Does it reduce sewage entering the lake? Does it restore habitat? Does it expand genuine public access to the shoreline? And does it treat the lake as something held in trust, a relation, not a resource? #BillyBishop #July24
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