A mechanism to re-order data records/search results by field would be useful.
Display linked media in a gallery or a new tab by default. Javascript could be employed, but this might be most effective using pure CSS.
Make it possible to scroll through search results without having to scroll down past the map and filter lists. I imagine these two elements within a div that, as a whole, can be made hidden or unhidden. This can be done using javascript, but also through CSS using a handy checkbox hack. Might also be handy to have an option for popping results out into a new tab.
Under a record's 'main observations' section, it would be nice to be able to directly search for other records with the same key:value pair in a designated context.
Some minor suggestions that might go a long way: