I have to admit, this summer has been a little different for conditions in the Keys. Seems to me the visibility is day to day more so than I&#x92;ve experienced in previous summers. </p><p>Spectacular one day, a little off the next day, add a bolt of current, then back to great conditions. Overall it&#x92;s been a terrific summer, just a bit different than my previous two summer seasons here.</p><p>One thing I&#x92;ve noticed is a lack of large group activity from eagle rays. Last year we saw groups with numbers in the dozens. This year I&#x92;ve seen smaller groups &#x97; twos and threes mostly &#x97; with a bit less frequency.</p><p>The other thing I have noticed this year is more big schools of glass minnows in different places.</p><p>All of you, by now, know my passion for Deep Molasses. It&#x92;s just a different world out there. And this summer we&#x92;ve had some pretty nice minnow action at about 70 to 80 feet along one of the slopes.</p><p>The last time I was at the Minnow Cave at North Dry Rocks &#x97; for an underwater anniversary celebration with Amy Slate&#x92;s boat &#x97; the minnows were there, but not as prolific as in times past.</p><p>The Spiegel Grove and the Benwood have been really hopping these last few weeks. On the helicopter deck behind the cranes on the Spiegel Grove it&#x92;s been a show in motion and muted light. Most of the action has been in the 75 to 90 foot range. Horse eye, yellow and bar jacks have been raiding the minnow pool. We&#x92;ve seen black grouper milling around on the deck, then plunging through a hole and nailing the school below. </p><p>Stealth technology is alive and well on the Spiegel Grove.</p><p>The schools are comprised of different species on the Spiegel Grove, and even a small school (a hundred or so) of juvenile grunts has been hanging out on the starboard crane. Fairly good numbers of speedo mackerel also come whipping through.</p><p>On the Benwwod, Chris Parson&#x92;s video is quite an eye opener. You will really enjoy this. My still images paint a moment in time, but Chris&#x92; video is full of life. Check it out here:http://vimeo.com/47724721#</p><p>As I am watching these hordes of minnows and thinking about the differences between this summer and last summer I, as usual, go off on a tangent. I&#x92;m wondering why this summer is so different than last summer.</p><p>I started by looking at bay anchovies and found a dissertation by Christopher Kelble from the University of Miami. His work is very interesting, and encompasses far more than anything I could theorize (no surprise there, right?).</p><p>I don&#x92;t know if these particular anchovies are the massive schools we are seeing on the reefs and wrecks, but from what I gathered from other journals, many of these species share similar behavioral and feeding characteristics. In the REEF identification book, they lump 10 species from three families into the minnow category.</p><p>Dr. Kelble&#x92;s extensive study of Florida Bay centers on the efforts to restore the Everglades ecosystem and deals directly with salinity issues. His focus is on the Comprehensive Everglades Restoration Plan (CERP). Their mission is to restore the quantity, quality and distribution of freshwater into the Everglades.</p><p>I wish I had more space to devote to his work, it really is worth the read. Get a big cup of coffee and grab the pdf file here: http://scholarlyrepository.miami.edu/oa_dissertations/392/</p><p>As Dr. Kelble points out, the variability of salinity levels in Florida Bay is incredibly important to the food chain. What does this have to do with minnows? Well, everything. He examined the relationship between mesozooplankton, salinity and bay anchovies.</p><p>What follows is a massive oversimplification of his work, but after spending quality &#x93;Issac time&#x94; last weekend with his dissertation, I think it&#x92;s important to try to distill this to terms even I can understand.</p><p>He begins with a history of salinity changes going all the way back to the effects of the overseas railroad. Next he covers the canal system that was built in south Florida during the land reclamation projects to enhance the agricultural base in the region. He finalizes the backdrop with a discussion of the ecological implications of CERP.</p><p>The ecological implications center on the relationship between salinity, mesozooplankton and bay anchovies. He demonstrates that future changes in salinity levels &#x97; lowering the salinity by raising the freshwater flow into the bay &#x97; could have significant effects. </p><p>Here&#x92;s why: the bay anchovies that feed on the mesozooplankton prefer lower salinity over higher salinity. So if CERP begins to significantly lower the salinity, more anchovies will eat more mesozooplankton. Less mesozooplankton will be around. They eat phytoplankton, which is a good thing, since phytoplankton are the culprits in algae blooms, which CERP also wants to reduce. But if there are less mesozoos feeding on phytos because there are more anchovies, we&#x92;ve got a problem. Wow, what a circle!</p><p>This is a mixed bag and a very complicated mesh of desired outcomes. Part of this matrix includes algae blooms on one end and the entire trophic food chain that begins with the minnows feeding on mesozooplankton and elevates up to snook, mackerel and other species with high commercial and recreational value. Those poor little glass minnows are literally caught in the middle.</p><p>The next time you see that school of thousands and thousands of glass minnows, you know not only are they amazingly entertaining to observe, but are also critical to the food chain, and our way of life in the Keys.</p><p><i>Tim Grollimund is a freelance photographer and PADI divemaster based in Key Largo. He can be reached at tim@timgimages.com or through his web site at www.timgimages.com. Tim is actively involved with the Coral Restoration Foundation and the Aquarius Foundation.</i>