The most obvious way we can establish and maintain a healthy coastal ecosystem is by recycling all recyclable materials and trying to live with as little waste as possible. Also, using clean transportation, such as biking and such, would help slow down air pollution; giving sealife clean air to breathe.
I believe it is D. More African elephants today naturally lack tusks compared to the elephant populations 100 years ago, because big game hunters sought elephants for ivory.
The leaves are smaller, meaning the plant cannot photosynthesize as fast as before. This means that the plant cannot produce as much energy and grows slower as a result.
Rate of growth of a seedling over two weeks