The question isn't worded very clearly. Scientifically you cannot talk about crop rotation for natural ecology. Ecology has mutualism, commencalism, companion plants that grow together, i.e. some lichen that have three organisms together, plant, mushroom and bacteria, in sponges growing on trees and on rocks.
Crop rotation is especially important on land because we do monocultures, and our sewage doesnt go back into the field, there is a net drain on the soil minerals. In forests and the sea, the situation is different, because plants adapted to the soil grow and build up nutrients over time by rotting with organisms, being fertilized by worms, snails, insects birds and so forth. In the sea, fish provide that function and there isn't the same net drain on a sea environment as there is in a crop.
If you study green life inside different pots of water, from river, tap, rain, and pond, from different sources and different geologies, you will learn some things about aquatic ecology and nutrients. It reacts with different plants and at different speeds.
The sea is physically so different from land, that the matter falling from the top can be transported miles away, that little comparison is made between nitrogen fixing in soil and in seawater. Also, the zone with the most light also has the strongest currents, so less chance for exchange of nutrients in ecology micro-climates and biomes.
crop rotation is mostly for N P K fixation.
On land NPK availability is often due to the acidity of the geology, which is not quite the same in the sea, plants can live on basalt or chalk, but they have endless flowing water and a good detritus layer in either.
In the sea, NPK is mostly brought by algea and cyanobacteria, which fall and bring it to the phito-detritus layer.
There are not the same forest type ecosystems in the sea as on land, where forests create many meters of peat bogs and massive NPK reserves, as in jungles sometimes. Because forests are less complex in the sea, less green stuff exists on the sea bed, we can say that the situation for plants is less profitable than on land and that instead the biomass exists more in floating small algea, Coccolithophores and so forth, which account invisible for most of the algal biomass of the sea. I cant find if there is more phyto biomass in the land or in the sea. I figure it's on land.
In freshwater environmetns, lakes can have an over or under abundance of NPK, and can bloom more or less completely for a given Ph and environment, given specific adaptations that help them to cope with a particular Ph. it's a lot more variable that the sea with PH going from 4 to 10 and beyond, when the sea ph is about 7.5-8.4.