Question

You are trying to help a friend sort some specimens in her lab. She collected organisms from a lake and forgot to label the sample with the part of the lake from which they were taken. Please select the item below that is correctly matched with its collection zone.

periphyton labeled "open water"

phytoplankton labeled "littoral zone"

anaerobic bacteria labeled "limnetic zone"

zooplankton labeled "limnetic zone"

cattails (emergent plants) labeled "profundal zone"

Which of the following statements about estuaries is NOT true?

Most estuarine species are pelagic.

Salinity is the most important factor in determining the distribution of estuarine species.

Often rivers flowing into estuaries provide relatively few nutrients other than phosphorus.

Oysters can be a dominant organism and form reefs wherever the bottom is hard.

Estuaries occur where coastal marine waters are semi-enclosed and are diluted by freshwater flows

Answer 1

1. zooplankton labeled "limnetic zone"

Zooplanktons are found in limnetic zone. The limnetic zone exists beyond the littoral zone and down to the light compensation level.

2. Often rivers flowing into estuaries provide relatively few nutrients other than phosphorus.

Phosphorus enters estuarine waters when freshwater runoff passes over geological formations rich in phosphate or when decomposing organic matter gets flushed into rivers and streams.