Click here for Merit McCrea – WHEELHOUSE SCOOP

Wednesday, September 11, 2019
Sorrow and grief
Wednesday, October 2, 2019
Told you so!

Land vs. water
The question here is which produces the most food, both when left in their natural state and when modified by agriculture/aquaculture. Then, how does wild and natural water do when compared to agriculture.

So what do plants do for a living? Some are single celled and float in water. Others are immense, with root systems reaching deep under ground and tops towering over 300 feet in the air with trunks as big around as a garden shed.

But all do one primary thing. They bust apart water and carbon dioxide with the sun's energy and make sugar — glucose. And those glucose molecules are then strung together to make either amylose, which is starch, aka food, or if linked a little differently, making cellulose, which is what wood is.

Now, starches and all the different stuff living things make by reprocessing sugars and starches are easy to process as food.

As for cellulose, it's a challenge. And those linkages are so difficult to bust apart — take so much extra energy that few animals can digest it — usually only with the help of specialized bacteria in their digestive tracts. And when they do the process is painfully slow and they don't get nearly as much food value back out of the deal.

First, the land. Plants are all about air, water and sunlight. That's really just about it, but for a little nitrate and phosphate. But on land, the competition for sunlight is fierce and plants are ruthless. Almost every green plant on earth isn't satisfied to have just the light that hits the dirt where they sprouted. They have to reach out and up — take all they can get — beat their neighbors to it, shading others out as they race for the sky.

Some grow fast for a year, or maybe just for a few months while the ground remains wet from winter rains. Others invest hugely in supporting structures that dig deep for water and high over all others, allowing them to last from year to year. Some cheat and climb other plants to get to the treetops without building a trunk.

But all of them are hell-bent to use all they produce to grow woody stems and support structures that are all about fighting gravity into the sunlight. They only grudgingly give up primary production to produce anything really worth eating.

Sugars and starches and proteins have to be available in their seeds and some in leaves. Some make fruit to induce animals to cart their seeds off with the fruit and distribute their progeny far and wide. Others sacrifice extra seeds for the same purpose.

Those that do the best job of making food rather than simply stems are the ones agriculture cultivates, and yet these plants still make far more leaf fiber, stems and trunks than food. Ranching cattle and such that eat grass allows the conversion of some of that cellulose back into food. And though their presence changes the natural ecosystem to grassland dotted with bigger trees, a great variety of wild animals share such range land, unlike the land under the plow.

Nevertheless, we've wiped out nature on almost every patch of flat dirt where water can be obtained, to grow those special food producing plants. That's agriculture.

In the marine environment, there's no gravity to fight. By far the greatest bulk of marine plants are tiny phytoplankton. Almost no marine plants make cellulose, aka wood. The rare exceptions are the few coastal ones which are descendants of terrestrial plants, and they don't make much of it.

It's all easily digested food for marine critters. Very little of it hangs around uneaten the way land plants’ woody carcasses do ashore.

So primary production doesn't pile up as deadfall. It almost all gets eaten — eventually becoming part of an edible fish or other critter. Wild marine environments blow away wild terrestrial ecosystems for food production.

Wild oceans even beat most agriculture when it comes to producing high quality protein. And while fishing does change the marine ecosystem, this change is trivial by comparison to what agriculture does to once wild terrestrial ecosystems ashore.

When it comes to being eco-friendly, fishing is by far the winner over agricultural meat production. So what about aquaculture? Is it an eco-winner too?

The answer here is it depends. Growing seaweed is a winner. So is growing filter feeders that eat wild plankton, stuff like mussels and oysters.

Growing fish can be an economic winner, even though it might not be the least impactful on nature. Feeding and caring for fish can mean less fuel and work than going out and catching them.

But fairly often the deal is they're catching wild fish to feed aquaculture fish, or at least growing grain to feed fish like tilapia.

The top winners as far as protein production goes are wild-caught fish, aquacultured filter feeders like oysters and mussels, and range-fed animals that eat grass and bush. These are the major protein sources which require the least bulldozing and plowing to produce and allow the greatest level natural ecosystem function and diversity.

Hunting would count too, but for the fact wild terrestrial ecosystems could never produce enough wild game to feed the masses. Those ecosystems make mostly tree trunks, deadfall and brush piles that ultimately catch fire instead. Without agriculture and fishing we'd never be able to feed ourselves.

Nevertheless, seriously reducing the number of top predators to support excess production of game is a far cry from eliminating every living thing but feed corn, or garbanzos, or grapes, etc. the way big ag. does.

What's surprising is the crazy driver of the difference between wild land and wild sea, is simply terrestrial plants' need to defy gravity as they compete for sunlight.

It's darned hard to beat the natural food production of marine environments — even with agriculture which ploughs under all that was once wild.

Fisheries' impacts on wild marine ecosystems are absolutely trivial as compared to what we do with fence, plough and pesticides ashore. The price nature pays to feed us is far less at sea.

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Merit McCrea is saltwater editor for Western Outdoor News. A veteran Southern California partyboat captain, he is a marine research scientist with the Dr. Milton Love Lab at the University of California at Santa Barbara’s Marine Science Institute. He can be reached at: merit@wonews.com.

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