WaterNotes

The collection trip was held over the past weekend in Brevard County Florida on (and in!) the Indian River Lagoon (IRL) system. I had such a blast collecting seagrasses and mud for the grass tank and had quite some time with the local fisherman.

“What d’ya want the weeds for?” “Honey why are you knee high in mud?” “Darlin dont you know there’s gators down here this time of year.” “The manatees have been known to attack right at that spot you’re poling through.” Ahhh locals.

Most of the habitats I visited were seagrass flats and mangrove estuary sites, which are typified by very little wave action, low volume differences through tidal cycles, high nutrient levels and very high dissolved organic compounds in the water. The water in all the spots I sampled in the northern IRL held salinity at 28-31ppt, pH at 8.2 across the board and temperatures near 64F. Keep in mind this is in the very early spring season for Florida so the salinity is a bit above what it would be in summer, just as the temperature is considered cool in comparison. Temperatures at 64F are in keeping with ocean temperatures at this time of year as well.

The grass flats are composed in broad bands delineated by depth. Halodule beaudettei (shoal grass) is defined in most spots by the low tide point and I was finding it as shallow as one foot at low tide. Manatee grass (Syringodium filiforme) was just beyond occurring around three feet of depth. Turtle grass (Thalassia testudium) isnt found in the northern area of the IRL, and I didnt see any errant patches of this. However a species of Caulerpa was found growing right alongside shoal grass in broad beds directly in the sand. This was pretty interesting, I didnt collect any specimens of this so I am not sure at this point if this macroalgae occurs naturally in the lagoon or was introduced. The Fort Peirce Smithsonian webpages dont list it as a normal species in the grassflat communities as far as I have read.

Fortunately I did not have to do any snorkeling, diving, or even deep wading in order to collect seagrass of anykind. A few days before I arrived the area had had high winds and rain and, apparently, some strong currents. Lots of seagrass “colonies” were washing up on shore in different areas I visited. By ‘colony’ I mean a rhizome set of plants, at least five connected leaf sets or blade sets altogether with roots. All I had to do was collect them out of the surf. I didnt really feel bad about this since literally pounds of these were washing up on shore, I felt that taking a couple ounces to try out for propagation in a home aquarium wasnt too much of a dent in the ecosystem!

Stargrass (Halophila engelmanni) also found its way to the shoreline and I collected several small colonies of this species. I plan on trading out some of the extra colonies to other hobbyists in the hopes that at least one of us will get it right and be able to grow and propagate this beautiful species. Coming from an aquascaper’s perspective this is an ideal species for a seagrass tank as its very beautiful, has interesting leaf shape composition and is a very small, low growing plant that would work well in a foreground placement in a tank. The leaf sets in this species are perhaps the size of a quarter.

Terrible picture of shoal grass..

Mangrove aerial root photo

Mangrove shoreline

Stargrass!

Bucket full of seagrasses..

As far as animals there were lots of juvenile horseshoe crabs (Limulus polyphemus), unknown saltwater insect larvae – most of which looked to be dragonfly or mayfly, snails of an unknown assortment, sheepshead minnows and the state protected Rivulus marmoratus. The Rivulus killies are especially interesting as the females are capable of producing clones of themselves without input from the males. I also sufficiently freaked out a local fisherman who was seining for grass shrimp in one grass flat area and was pulling up dwarf seahorses and lined seahorses (Hippocampus zosterae & erectus). That was a very cool experience, and sadly, since I was still scouting locations, I didnt have my camera with me to take pictures.

I went back the next day to collect a few dwarfs prior to leaving for home but I was only able to pull up five dwarf seahorses and I didnt feel that the colony in the area was large enough to allow for me to take all of the ones I was netting. Afterall, I dont want to be the reason that the dwarfs go extinct in that local spot. So I’m very excited about setting up the tank with the lagoonal mud I brought back as well and getting these plants under lights and going.