Endangered Sundays: Manatees

A new feature for the blog: an irregular look at endangered species and how climate change is predicted to further affect them.

three manatees - two in the foreground, one in the background

Manatees - threatened in Florida

Manatees are native to Florida, and have no native predators there. They are endangered because they are slow-moving and thus easy victims to propellor strikes from boats, and also because their food supplies are threatened by toxic pollutants and climate change.

Some individuals have tried to simplify the effects of climate change on manatees by assuming that warmer waters will benefit the species.

However, as the previous paragraphs discussed, climate change is comprised of many more facets than just increasing water temperatures. We also cannot forget that manatees are part of an inter-connected aquatic ecosystem, and are affected by the health of the plants and animals that share this and the surrounding terrestrial ecosystems.

As a species, manatees already face a myriad of threats, including watercraft strikes and red tide, which may compromise the long-term health of individuals and impede recovery of the species. As humans adapt to climate change, other species, including manatees, are likely to be adversely affected.

While some have postulated that increased sea surface temperatures associated with climate change may benefit manatees, this view fails to recognize how the species may be affected by the myriad of other consequences associated with climate change, including sea level rise, changes in seagrass abundance and location, and losses of funding as agencies shift resources away from individual species in an attempt to confront climate change.
Source: current.com

The last sentence is the crucial one. The planet has already lost a staggering amount of biodiversity since the beginning of the Industrial Revolution started churning toxins into the environment at an unprecedented rate, and now we are starting to see staple food crops become threatened as well as seeing ecosystems wildly unbalanced by our over-predation of food animals and displacement of competing apex predators – just look at the effects of losing (and then repopulating) the Yellowstone Wolves on willows, cottonwoods and aspens in the Park for an example of how much an ecosystem can change according to the active predators in the region – more wolves means more trees.

As climate change reduces global food supplies, the apex predators will be the first to die out (because at the top of the food chain the dependence on protein is so high). We don’t know exactly how most ecosystems will adjust to losing them. The potential for cascading catastrophe is enormous, especially if current threat mitigation programs are defunded in order to concentrate on climate threats alone.

We are close to tipping points for so many local ecosystem aspects of what humans need to be a sustainable global ecology. Dont’ be complacent.

Categories: environment

Tags: ,

4 replies

  1. Count me as a fan of Pessimism Sundays. It’ll make the rest of the week seem really good, at least.
    I like manatees. They look like someone made them out of play-dough, halfway to some other shape.
    Perhaps one Sunday you could do tuna?

  2. I have always appreciated the idea that manatees (or dugongs, who apparently have similar behaviours) may have been the actuality behind the myth of mermaids.
    Makes me wonder if one of the reason we are apparently getting into climate trouble is because only certain standards of “beauty” are/have been acceptable.

  3. Long comment coming up I’m afraid.
    I live on a property on the edge of a cliff above what used to be a wetland backwater of the River Murray in SA.
    As a keen birder and environmentalist I have kept a close watch on the bird species at our place and recorded a 127 species with about 30-40 of them being waterbirds. Scientists have conducted baseline biodiversity surveys here several times.
    A few years ago we had a bat detector at our place for a week on two separate occasions. Its a machine that records the ultra sonic calls of bats and thus allows the species to be identified because each has its own distinctive call.
    We had [past tense] 8 species of bat resident here.
    One of the species was the Large footed Fishing Bat [Myotis macropus] which was the second time it had been recorded in this region [the first time was the previous week when the machine was at a neighbouring property] and is rated ‘vulnerable’ [or similar] in other regions.
    Now thanks to 3 factors:
    -overallocation of river water to irrigators
    -recent drought in the Murray Basin
    -climate change resulting in longterm reduction in rainfall in the Murray Darling basin
    our ‘wet’land has been dry for 3 years.
    As have all the other ‘wet’lands’ in this stretch of the river.
    The consequence is that several bird species have locally disappeared or drastically reduced in numbers.
    About 30 species which used to be common are no longer seen.
    There is no water for them.
    And also disappearing have been the turtles, frogs, water rats, water snakes and any species reliant on a lagoon habitat.
    Including, sadly, the Large-footed Fishing bat.
    For me, species depletion is a phenomenon I can observe every day.

  4. I’m so glad you have those cheerful hats in the previous post, tigtog. The state of the environment leads me to despair. I’m very angry about the IPCC/glaciers mess; I can’t help thinking that it will be virtually impossible to get anything done with respect to climate change now.

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