eggs and larvae
... that the eggs and larvae of fish can be sampled as an index of the relative abundance of spawning adult fish?
... that the <b id="mwDH4"><a href="./Ichthyoplankton" id="mwDH8" rel="mw:WikiLink" title="Ichthyoplankton">eggs and larvae</a></b> of fish <i id="mwDIA">(salmon larva pictured)</i> can be <a href="./Sampling_(statistics)" id="mwDIE" rel="mw:WikiLink" title="Sampling (statistics)">sampled</a> as an index of the relative <a href="./Abundance_(ecology)" id="mwDII" rel="mw:WikiLink" title="Abundance (ecology)">abundance</a> of <a class="mw-redirect" href="./Spawning" id="mwDIM" rel="mw:WikiLink" title="Spawning">spawning</a> adult fish?