on/in the pond

There is a flock of geese -on- the pond.
There is a lot of fish -in- the pond.
Are the prepositions in the above sentences OK?

dear teacher.
flock of geese means plural form of ghoose? right or wrong? if wrong means what is that meaning of flock of geese?
warm regards
kavitha

goose - singular
geese - plural
flock of… the collective noun for a number of geese.

Mr. Beeesneees,
Please confirm the validity of those prepositions.
Are they correct?
Thanks.

Here are the singular/plural verb forms and prepositions:

There is a fish in the pond/sea/river/water/lake, etc.
There are a lot of fish in the pond/sea/river/water/lake, etc.
There is a shoal (collective noun - one set) of fish in the sea.

There is a goose on the pond/lake/water/river, etc.
There are a lot of geese on the pond/lake/water/river, etc.
There is a flock (collective noun - one set) of geese on the pond.