NAPOWRIMO Day 6 poem

This one was tough. Marianne Moore's style looks relatively straightforward, but trying to stick to a similar style forced me to stop thinking in metaphors which was tough. So far this day 6 poem is the farthest from my own style. Here's my poem:

Manatee

Eight feet of placid sea cow, round and slightly whale-like with a much smaller head.
They graze along the Eastern Atlantic seaboard in rivers
and inner coastal waters from Florida to Brazil. Another species exists
on the West coast of Africa. A third species in the Amazon.

Shallow dwellers, manage to swim their eight-foot bulks
with grace as they consume one-tenth their weight each day
in sea grass, algae and weeds.

Calves born underwater suckle milk; must be helped to the surface
by their mothers for their first breath of air. Then in only an hour
the calves can swim. An adult manatee surfaces every three to four minutes.
If resting on the bottom waters they can wait fifteen minutes to surface.

Slow-moving manatees swim from five to fifteen miles per hour.
Their tails provide the power.

Forty year lifespans - unless
a hunter, fishing net, or power boat motor shortens
their lives.

Shallow dweller, alone or in a small group,
survive in water forever with only nose and nostrils visible;
they are not rocks, not a rock, not a rock.