Odd situation on fish fry and name that algae

[Nanner]

So I have a 300+ gallon above pond with a veggie filter. Goldfish plain and fancy and some minnows fathead and rosie's reds. This spring I have had Robins destroying my plants in my veggie filter while bathing and playing. So today while cleaning it up again and trying to build a protective area for the plants to hopefully bounce back with sticks...I noticed I have at least 3 fry in my veggie filter top area. No way they can could have been sucked in and got through volcano rock, scrubbies and gravel ? Right? So guessing transfer from birds?

99.9 % they are fry. definitely not mosquito larvae also no frogs so no tadpoles.

Just very odd...so what are your theories on how they got there?

Tried to get photos of them but they seem to disappear in the photo. I'll try again this eveing.

Picture of my pond for reference

Also the close ups are the ones with the fry in there but they get washed out.

Also what is the stuff settling on the bottom of my veggie filter?...been terrible this year with the birds.... guessing some type of algae from larger nitrates the birds introduce that get trapped and not filtered through since it stays in the top of the veggie container. If I stir it up it floats to the pond.

Alson an Example of my veggie filter build.

Many thanks

 

[Nanner]

Also no new plants introduced in veggie filter in 3 weeks

 

[j.w]

I think the birds did it. Eggs are sticky and bird legs travel to and fro.

 

[addy1]

what is the stuff settling on the bottom of my veggie filter?.

My bog has for years had the surface of the pea gravel get covered with a fine muck. A lot settles as the water flows over it. If it gets stirred up it goes into the pond and gets filtered right back out.

I also get fish eggs everywhere, every now and then I get a fish where no fish ever where.

 

[Nanner]

Nature is a lovely strange dance partner...
Just glad we get to be part of it.

Thanks for the replies