#It's actually quite a common (and effective) defense mechanism against sharks!

[albertsmarinebiologydump]

I saw a video of a marine biology student almost get The Meg'ed by a curious shark and the student just swatted the thing on the nose like a bad dog.

Is that... normal??? I mean, it worked. The shark was like "my bad dude" and wandered off.

That's normal! It's because sharks have extremely sensitive noses, just like dogs. It practically overstimulates them, which makes them back off.

[diana-miad380-blog]

Why is UWM Planting Native Plants Around Campus?

Question #3: Why is it important to plant more native plants? Why do we need to manually add to their population? How important are they really? If a similar invasive plant moves in is that really such a bad thing?

“Native plants are those that occur naturally in a region in which they evolved. They are the ecological basis upon which life depends… without them and the insects that co-evolved with them, local birds cannot survive. For example… native oak trees support over 500 species of caterpillars whereas ginkgos, a commonly planted landscape tree from Asia, hosts only 5 species of caterpillars. When it takes over 6,000 caterpillars to raise one brood of chickadees, that is a significant difference” (Audubon).

Benefits of planting native plants in your yard/home garden: they are ecologically designed for that environment and are therefore low maintenance, require less (non-rain) water, and less chemicals including pesticides, artificial fertilizers, herbicides, and other chemical additives. They also support wildlife better than any invasive plant ever could.

What’s the problem with invasives?

Primarily, they have no predators in their new environment/ecosystem. They did not co-evolve with everything around them, they don’t have a niche, an ecological purpose, and shoving their way in disrupts the balance and threatens the area’s biodiversity. A classic example of this co-evolution is the cheetah and the antelope, over time, they both became faster, the antelope as a defense- to better run away and escape, the cheetah as an offense- to better catch up to and kill the antelope being able to eat and sustain its needed energy. It’s a continuous process, with neither species gaining a true upper hand, leading to a balance in their natural world. But when a predator is suddenly given a brand-new prey, its evolved advantages don’t make sense; they have no means to take as much advantage as possible of it. The same is true in the reverse, defense mechanisms against specific predators don’t work effectively against something newly introduced. For example, many trees have generated built in defenses to local/common insects, fungi, and some diseases. They are not protected against all, just the ones in their area. So, when either put in a new area or with a new threat added to theirs, these trees become extremely vulnerable. Entire forests have been destroyed in record time because of this phenomenon. There’s another kind of organism too, one that can actually alter the environment itself and make it more favorable to their needs. The Yellow Starthistle secretes a chemical from its roots that is extremely harmful to plants without an evolved immunity. It kills off all the plants around it, clearing space for it to expand. In an area without immune plants and without natural predators, the Yellow Starthistle can expand exponentially, destroying everything in its path.

So that’s why invasive plants are bad, but why keep planting native ones?

Keeping the balance, a stable state, of an ecosystem is the best thing one can do for it. It’s quite possible for an invasive species to result in the extinction, at least at the local level, on a native one. We know that something like that causes a chain reaction, sometimes a huge one depending on what and where. I was thinking about Darwin and his finches, about how from two different islands they had two different beak shapes, which he believed to be the result of the size/shape/hardness of the seeds; their available food. Imagine that an entirely new seed-producing plant with very different seeds is introduced; if it were to do well and overtake the island, out-compete the original plants for resources and became the predominant seed on the island it would affect the finches greatly. They’re designed for the original seed, they co-evolved together. They would be very ineffective at eating this new seed which has now become their only resource. Their population numbers would suffer, causing anything and everything else on the island that depended on the finches or used them in some way to have drastically and suddenly lowered populations as well, and the same with the next chain, and the next. That island’s ecosystem would collapse, it would likely suffer several extinctions or near extinctions, all because of the limitation of a single native plant. That all brings me to another ideas, which if the finches didn’t even realize they could eat this new seed? It’s entirely possible, as a something unfamiliar, they don’t acknowledge it as a food source.

Last year I did a science research project on the Lionfish’s invasive presence in the Gulf of Mexico. Now, they aren’t plants, obviously, but the principals remain the same. One of two major problems with them was that they had no predators. They had predators in the Mediterranean areas, where they co-evolved with the other marine life. Some of those predators are even found in their new environment off the coast of Florida, but they weren’t eating the Lionfish, why? Simply because they were new and unfamiliar. The sharks of the East-coast Atlantic did not co-evolve with the Lionfish as the Mediterranean sharks did, they flat out don’t recognize the Lionfish as something that they can eat and instead continue to eat only their familiar prey. I wonder if that same thought or process would apply to “predators” of plants? It seems likely that many invasive plants could be food or nest material or something for the smaller animals and insects but aren’t simply because the animals have never seen it before, they don’t know what, if anything, they can do with it.

Continuing to add native plants to our environment helps to mitigate the damage already done by invasives, plants and animals alike, and help to slow any further damage. Invasive species get to where they are almost exclusively due to humans, it’s our responsibility to do what we can to remedy the situation. We must preserve the balance.

 https://www.audubon.org/content/why-native-plants-matter

https://www.environmentalscience.org/invasive-species