Invertebrates associated with beach wrack are a good indicator of upper beach conditions and an important prey component for shorebirds and other animals. Passive pitfall traps are used to collect mobile invertebrates during an ebbing tide when the upper beach is exposed. Invertebrate abundances may vary depending on the amount of beach wrack and logs, substrate type, shoreline armoring, and other habitat features. Analysis can focus on counts of beach-hopper amphipods or include other invertebrates such as insects and collembolans as well.
Beach hopper identification
There are three main species of Talitridae amphipods in central Puget Sound. Details on identifying them can be found here.