How Climate Warming Targets African Fishermen

December 2, 2019

Washington Post:

TOMBWA, Angola — His ancestors were Portuguese colonialists who settled on this otherworldly stretch of coast, wedged between a vast desert and the southern Atlantic. They came looking for the one thing this barren region had in abundance: fish. 

By the time Mario Carceija Santos was getting into the fishing business half a century later, in the 1990s, Angola had won independence and the town of Tombwa was thriving. There were 20 fish factories strung along the bay, a constellation of churches and schools, a cinema hall built in art deco, and, in the central plaza, massive drying racks for the tons upon tons of fish hauled out of the sea. 

Since then, Tombwa’s fortunes have plummeted; Santos’s factory is one of just two remaining. The cinema hall is shuttered. Kids run around town barefoot instead of going to school. The central plaza is overgrown by weeds, its statue of a proud fisherman covered in bird droppings. 

“Six or seven species have disappeared almost entirely from here, sardines and anchovies included — the ones these factories were made for processing,” Santos said in his office, after inspecting the day’s catch. 

“We’ll just have to close shop at some point.”

The gradual disappearance of fish is a death knell for Tombwa, a town of 50,000 that has little else to offer residents. The approaching bust is the result of three powerful forces: Fish are suffocating in oxygen-depleted waters, huge foreign trawlers are grabbing what’s left, and the water is heating up far more rapidly here than almost anywhere else on the planet. 

Click any temperature underlined in the story to convert between Celsius and Fahrenheit 

Sea temperatures off the Angolan coast have risen 1.5 degrees Celsius — and possibly more — in the past century, according to a Washington Post analysis of National Oceanic and Atmospheric Administration data. 

In recent years, multiple studies have identified the waters along Tombwa’s coast in particular as a fast-warming hot spot: In one independent analysis of satellite-based NOAA data, temperatures have risen nearly 2 degrees Celsius since 1982. That is more than three times the global average rate of ocean warming.

Ocean warming in key hot spots around the globe — from Canada to Japan to Uruguay, where temperatures have risen 2 degrees Celsius or more — is disrupting an array of fisheries, including lobsters, salmon and clams, The Post’s reporting has found. 

The impact is especially acute in Angola, among the most vulnerable countries in the world to climate change, even though the entire country’s carbon dioxide emissions amount to about 0.1 percent of the world’s output each year

The warming ocean temperatures compound the effects of two other ecological catastrophes playing out in this southern African country of 30 million: Illegal fishing depletes the ocean of tens of thousands of tons of fish each year, and increasingly oxygen-poor seawater makes coastal areas inhospitable to a diversity of marine life. 

Fisheries data from the southern coast of Angola, a country wracked by civil war until the mid-2000s, is sparse. But a number of species integral to the area are being hard hit by the disruptive consequences from this triple threat: 

● A species of fish critical to subsistence fishermen in Tombwa, the blacktail seabream, is losing its ability to reproduce here as waters warm: Its reproductive output is estimated to have declined by 20 percent per decade over the past 30 years. Instead, the fish are moving south, to cooler waters, according to a study by Warren Potts, a marine biologist at Rhodes University in South Africa. 

● The dusky kob, a massive fish that can grow over six feet long and is popular with anglers in southern Angola, is also shifting southward, sparking a bizarre evolutionary event: Two kob species that had been separated for some 2 million years have reconnected and are interbreeding, Potts has found. That development implies that warming levels here may have breached a new threshold. 

● Beyond the southern coastline, a species key to the Angolan diet has been disappearing from the country’s waters: Cunene horse mackerel levels in the region dropped from an estimated 430,000 tons in 1996 to 137,000 tons in 2013, a “historic low and critical level,” according to a technical report written to help Angola manage the species.

Ultimately, unchecked warming could also cause Angola to lose 20 percent of its fisheries, according to a recent study by Rashid Sumaila, an oceans expert at the University of British Columbia in Canada. The projection uses ecological and economic modeling to determine what could happen to fisheries if countries fail to cut emissions. 

Oceans are complex ecosystems, and marine life is highly sensitive to even the slightest shifts in temperature and oxygen levels. Potts, who is alone in studying the warming near Tombwa firsthand, says the chain reaction the changes will wreak here is hard to predict — but almost inevitably dire. 

“Imagine that one species of fish is able to adapt to the warming, but it so happens they’ve evolved to only eat another species that wasn’t able to adapt. Then what?” said Potts, 45, an avid fisherman who, like many South Africans, was initially drawn to southern Angola for its legendary angling.

7 Responses to “How Climate Warming Targets African Fishermen”

  1. terry123a Says:

    I will not argue about warming waters. what I would suggest is over fishing is the most likely cause of the fishery declines. Over fishing is the single most likely cause of any fishery decline worldwide. Most countries in the first world have put in place fishing limits to manage the fishing burden on the fish stock. Angola and the rest of Africa has not done that.

    Current warming is no greater than it was in the middle ages warm period and less than in the Holocene or around 4500 BP warm periods so ocean temperatures do change and the fish survived. They cannot survive if fishing pushes the adult reproduction fish below certain limits.

    • jimbills Says:

      Why do you keep changing your name but keep sticking to the same style of name? Just pick one already.

    • dumboldguy Says:

      H-e-e-e-e’s B-a-a-ck!

      Terry The Denier of Many Names is chipping in with more deflection and obfuscation. Yes, over fishing IS responsible for the decline and disappearance of many fisheries around the world. DUH!

      BUT—this is an article about a SPECIFIC location citing SCIENTIFIC evidence about what is going on there. We know you don’t like science, Terry, except to deny it, misrepresent it, or confuse it, but the evidence in the article IS clear—-or do you still have a reading comprehension problem?

  2. dumboldguy Says:

    This was the “ruin your day” piece in Sunday’s WashPost—-on page one. Disturbing in many ways, particularly in how well it illustrates the interconnectedness of so many factors and how much more we need to learn about them.

    Left out of this Crock piece was the WashPost info on the overfishing that is piled on top of the negative environmental factors, China being the culprit and sending huge factory fishing boats to the Angola coast—-Angola is unable or unwilling to stop them.

    • rhymeswithgoalie Says:

      It’s frustrating when environmental problems that have lots of contributing causes are used as examples of AGW/CC. The Gulf coast of Louisiana, for instance, is disappearing in part due to a number of longterm policy and political corruption causes unrelated to ocean expansion, record floods can be the result of terrain changes (always look at the rainfall amounts), some glacial melt acceleration is due to darker snow from anthropogenic sources.

      There are plenty enough examples that are tied more directly to AGW, like loss of Arctic sea ice leading to the trashing of the northern jet stream or ocean warming events bleaching large amounts of coral, accelerated aridification of Europe’s Mediterranean countries and the slowing of the Gulf Stream.

  3. terry123a Says:

    You may have something there about Chinese and other fishing vessels fishing within Angola territorial limits at sea. Now that you mentioned it I do remember reading something on the subject a while back. How to stop that over fishing is something that needs to be talked about and fixed. We did it to the passenger pigeons, almost to the buffaloes and plenty of other creatures in this country before we got laws in place and enforced for conservation

    Here is a source of temperature back 7000 years. I notice that it was much hotter on average 5000 years ago to 7000 years ago than it has been in the last 2000 years so perhaps the fish in this story spent most of their lives somewhere else than off Angola back than. https://en.wikipedia.org/wiki/Dendroclimatology#/media/File:Yamal50.gif

    • rhymeswithgoalie Says:

      The YAMAL PENINSULA IS NOT THE WHOLE BLOODY PLANET.

      It represents about 0.003% of Earth’s surface, and the area where the trees were measured is much, much smaller than that.

      Why do you think climatologists haven’t taken all these things into account? (By the way, the link to that Russian dataset is no longer available to check the scientific considerations about the data.)


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