Dynamics of Florida milk production and total phosphate in Lake Okeechobee

A central tenant of the Comprehensive Everglades Restoration Plan (CERP) is nutrient reduction to levels supportive of ecosystem health. A particular focus is phosphorus. We examine links between agricultural production and phosphorus concentration in the Everglades headwaters: Kissimmee River basin and Lake Okeechobee, considered an important source of water for restoration efforts. Over a span of 47 years we find strong correspondence between milk production in Florida and total phosphate in the lake, and, over the last decade, evidence that phosphorus concentrations in the lake water column may have initiated a long-anticipated decline.

Dynamics of Florida milk production and total phosphate in Lake Okeechobee

A central tenant of the Comprehensive Everglades Restoration Plan (CERP) is nutrient reduction to levels supportive of ecosystem health. A particular focus is phosphorus. We examine links between agricultural production and phosphorus loadings in the Everglades headwaters: Kissimmee River basin and Lake Okeechobee, considered an important source of water for restoration efforts. Over a span of 47 years we find strong correspondence between milk production in Florida and total phosphate in the lake, and, over the last decade, evidence that phosphorus in the lake may have initiated a long-anticipated decline in water column loading.

Two New Cassis (Gastropoda: Cassidae) and a New Malea (Gastropoda: Tonnidae) from the Pliocene and Pleistocene Beds of Southern Florida

Two new fossil Helmet Shells of the genus Cassis Scopoli, 1777 (Cassidae) and a new fossil Grinning Tun Shell of the genus Malea Valenciennes, 1832 (Tonnidae) are described from the Pliocene and Pleistocene fossil beds of southern Florida. The new Helmet Shells, Cassis rasae n. sp. and Cassis viliusi n. sp., were both collected in the rich fossil beds of the Holey Land Member of the Bermont Formation (Calabrian Stage, Early Pleistocene) and the new Grinning Tun, Malea hyaducki n. sp., was collected in the Fruitville Member (Kissimmee River Valley equivalent beds) of the Tamiami Formation (late Piacenzian Stage of the Pliocene). The discovery of two new large Helmet Shells in the Holey Land Member demonstrates that four species of Cassis are present in the Bermont Formation, making this the single largest fossil Cassis fauna found anywhere on Earth. The new Grinning Tun represents the oldest-known Malea found in Florida, and is the direct ancestor of the Gelasian Pleistocene Malea springi (Caloosahatchee Formation) and the Calabrian Pleistocene Malea petiti (Bermont Formation).

The Fossil Cypraeidae of the Fruitville Member (Unit 2) and Kissimmee River Valley Equivalent, Tamiami Formation of Southern Florida: (Mollusca: Gastropoda: Cypraeidae)

Unit 2 was the last member of the Tamiami Formation of the Late Piacenzian Pliocene. Its ending signaled the commencement of a two stage extinction event. The first stage wounding event resulted in the disappearance of the Akleistostoma (Gardner, 1948), Calusacypraea (Petuch, 1996) and Pseudadusta (Petuch, 2004) genera and the end of the Tamiami Formation.

The Fossil Cypraeidae of the Fruitville Member (Unit 3) and Kissimmee River Valley Equivalent, Tamiami Formation of Southern Florida: (Mollusca: Gastropoda: Cypraeidae)

Four species of the Pahayokea (Gardnericypraea) Petuch and Drolshagen, 2011 subgenus are reclassified as Akleistostoma (Gardnericypraea) subgenus species. This represents a continuation of geographically separate, but parallel, evolutionary tracks throughout the Piacenzian Pliocene Tamiami Formation

The Fossil Cypraeidae of the Fruitville Member (Unit 4) and Kissimmee River Valley Equivalent, Tamiami Formation of Southern Florida: (Mollusca: Gastropoda: Cypraeidae)

The disappearance of all Pinecrest and equivalent Cypraeidae species from most of their habitats was caused by the circa 200,000 year cooling period in the mid Piacenzian Pliocene, c. 3.2-3.0 mya, and the associated significantly lower sea levels and dry terrestrial conditions in southern Florida. The cooling period was followed by a warming period, which resulted in the Tamiami Subsea being flooded to its maximum size and produced wide-spread tropical conditions throughout southern Florida, roughly similar to today’s southwest Pacific. This resulted in the renewed radiation and speciation of the Cypraeidae populations. In the Myakka Lagoon System, the eight Pinecrest Member (Unit 7) Cypraeidae species in five genera were followed by ten new species in five genera which emerged in Fruitville (Unit 4) time. In the Kissimmee River Valley, the five Unit 7 equivalent species in three genera were followed by eight new species in three genera, which emerged in that area. The number of genera remains consistent at three with the only species previously assigned to Pseudadusta Petuch, 2004 placed into synonymy with Akleistotoma bairdi (Petuch, 2004). This represented a continuation of geographically separate, but parallel, evolutionary tracks.

The Fossil Cypraeidae of the Pinecrest Member (Unit 7) and Kissimmee River Valley Equivalent, Tamiami Formation of Southern Florida: (Mollusca: Gastropoda: Cypraeidae)

Following the disappearance of the seven Buckingham Member (Unit 10) Cypraeidae from the Myakka Lagoon System (Myakka), there was a hiatus represented by two strata at Sarasota (Pinecrest Members 9 & 8) in the early Piacenzian Pliocene, 3.6 million years ago (“mya”), from which no Cypraeidae have been recorded. This was followed by the warmest and most tropical conditions of the entire Pliocene. The sea grass beds and mud flats, which were the preferred habitats of the Pinecrest Cypraeidae, returned in force. The depositional strata which resulted, Pinecrest (Unit 7) and its Kissimmee River Valley Equivalent, were very thick and probably represent a long period of uninterrupted deposition. Eight new species in six genera emerged in Myakka. In the Kissimmee River Valley (Kissimmee), six new species in three genera (one new) emerged as the first and earliest known Cypraeidae species from that area. This represented geographically separate, but parallel, evolutionary tracks. Pinecrest Members 6 & 5 represented a repeat of the conditions experienced during Pinecrest Members 9 & 8, resulting in the disappearance of all Pinecrest (Unit 7) Cypraeidae from Myakka and Kissimmee.