First I would like to note that I have only very basic understanding of ecology, biology and paleontology so I can easily miss something very simple.

I can envision certain ways marine and terrestrial ecosystems influence each other:

  1. Rivers and surface runoff carries minerals, soil, plants, excrements etc into the oceans. Productive terrestrial ecosystem would mean less minerals, more organic nutrients going into the ocean.
  2. Terrestrial animals (like birds) eat marine ones and then excrete and are eaten at the land.
  3. Marine and terrestrial ecosystems absorb and produce atmospheric $O_2$, $CO_2$, $N_2$ that are redistributed globally by atmospheric movements. That also affects climate and therefore water cycle.

Naively it seems to me that the situation is quite asymmetric. While №2 should be of extreme importance to the coastal ecosystems I suppose it's influence drops quickly as you go deeper into continent aggravated by water currents taking everything back into ocean. So (again naively) it seems to me that marine ecosystems should be much more influenced by the terrestrial ones than the other way around.

So imagine sudden significant drop of primary production for some reason constrained to the oceans. Obviously it would be a catastrophe for island and coastal life but in what ways, how much and at what timescale it will affect inland ecosystems? What if we turn it upside down and consider some significant drop of terrestrial primary production?

  • $\begingroup$ This is probably too broad for a question. Consider focusing on just one aspect of it. $\endgroup$ – bon Dec 11 '16 at 18:19
  • $\begingroup$ If you just Google for things like carbon cycle or nitrogen cycle you have a good start $\endgroup$ – Jan Doggen Dec 11 '16 at 22:01
  • $\begingroup$ @JanDoggen Ok, I don't want to sound like a rude profane, but have you read my question or just read the title? Your comment is useless to me unless you add at least something like "Pay extra attention to that and that", "You miss that" or give good relevant reference $\endgroup$ – OON Dec 11 '16 at 22:22
  • $\begingroup$ @OON Agree. Too broad and unclear exactly what the question is. If you can narrow it down to let's say "what happens to life in X if the level of Y drops because of something thing". Answering your question will be a 20 page long paper. $\endgroup$ – Gimelist Dec 12 '16 at 5:54
  • $\begingroup$ @OON I read your question but it was unclear to me where your question hooks into these things. Maybe just a question of 'too broad'. Never mind, no offense. $\endgroup$ – Jan Doggen Dec 12 '16 at 8:54