Cockroach Bay Aquatic Preserve — Tampa, Florida

Cockroach Bay Aquatic Preserve is a state-protected stretch of shallow water on the eastern side of Tampa Bay in southern Hillsborough County, just south of the mouth of the Little Manatee River near Ruskin. The Florida Department of Environmental Protection (FDEP) lists it as established in 1976 and covering 4,871 acres, with a boundary that extends 2,000 feet into Tampa Bay from the shoreline and takes in several mangrove islands, most of them state-owned.

The preserve has a legal quirk found nowhere else in the Florida system. FDEP states that Cockroach Bay is the only aquatic preserve in which the submerged land is not owned by the State of Florida. Years ago, submerged land in Hillsborough County was ceded to the Tampa Port Authority, so bringing this area into the state's preserve system required a long-term lease between the port authority and the state. Management falls under FDEP's Tampa Bay Aquatic Preserves office, guided by a management plan that FDEP lists as fully approved on April 11, 2017.

FDEP gives the most widely accepted explanation: early Spanish explorers thought the abundant horseshoe crabs along this part of Tampa Bay resembled cockroaches. The same FDEP page records that people have relied on the area for seafood since pre-Columbian times and that the preserve holds pre-Columbian archaeological resources, whose exact locations are kept private to protect them from looting and vandalism.

Below the water, Cockroach Bay sits on old geology. FDEP describes Tampa Bay as a drowned shoreline: when glaciation lowered sea level, tributary rivers cut a valley into the limestone, and the rising sea of glacial retreat flooded it. At Cockroach Bay the surface layer is undifferentiated shelly sediment from the Pleistocene, while exposed limestone near the offshore boundary gives hard substrate species a place to attach. FDEP adds that ebb tide sediments from the Little Manatee River likely cover the nearshore edge of that limestone.

The fossil fame comes from the Leisey Shell Pit near Ruskin. A Hillsborough County historical marker series recounts that in summer 1983 fossil hunter Frank Garcia found Ice Age remains on land owned by the Leisey Shell Corporation, which was mining crushed seashells for road building. Some of the material was about two million years old. Finds included mammoth jaws, saber cat teeth and the remains of a condor with a 15-foot wingspan.

Volunteers, with local and state support, unearthed the remains of over 140 species, and Hillsborough County reports that 20 of them were new to science, including several birds, rodents and an armadillo-like mammal. The marker titled Miracle at Cockroach Bay, erected in 2017 by the Hillsborough County Historical Advisory Council and the Tampa Bay Fossil Club, states that one of the richest Ice Age fossil discoveries in the world took place in 1983 and 1984 in ponds that were once the Leisey Shell Pit, and that over 20,000 identifiable fossils were recovered with the Florida Museum of Natural History.

The marker stands on Mammoth Trail in Ruskin, 0.2 miles south of Gulf City Road. Hillsborough County notes that a collection of Leisey Shell Pit items can be seen at the Paleo Preserve Fossil Museum, part of the Camp Bayou Outdoor Learning Center, operated with Hillsborough County Conservation and Environmental Lands Management.

Shell mining also shaped the uplands beside the preserve. According to the SWFWMD WaterMatters magazine for May to June 2012, Hillsborough County purchased a 651-acre property in 1991, located just outside the Alafia River watershed boundary in southwest Hillsborough County, when it was largely agricultural fields and shell mining pits near the bay. The SWIM Program of the Southwest Florida Water Management District and the Hillsborough County Parks, Recreation and Conservation Department started the restoration.

At the 2012 dedication, SWFWMD described the Cockroach Bay project as 500 acres of coastal restoration, made up of 282 acres of estuarine and freshwater habitats and 218 acres of coastal uplands, built in 17 phases over 20 years, paid for in stages as funding allowed. Twenty-six groups and agencies took part, and more than 2,500 volunteers planted trees and wetland grasses. Crews hauled about 176 tons of garbage off the site and used 500,000 cubic yards of recycled dredged material to restore part of the mining pits; the final phase restored two shell pits funded by the Tampa Port Authority. The ceremony ended with the release of four rehabilitated brown pelicans.

FDEP lists the preserve's habitats as open sand bottom, seagrass beds, oyster reefs, hardbottom outcrops, mangrove shorelines and islands, set among tidal creeks, a blackwater stream and alluvial islands in this corner of Hillsborough County. Nesting and migrating birds include roseate spoonbills, reddish egrets and tricolor herons. Mammals include bottlenose dolphin, West Indian manatee and river otters, and FDEP records both the American alligator and the American crocodile. Snook and redfish are abundant around the Cockroach Bay mangrove shorelines.

Conservation work at Cockroach Bay focuses on resource mapping and monitoring, partnering on runoff and pollution, controlling invasive species such as the Asian green mussel and removing marine debris, according to FDEP. Volunteers help remove invasive plants on the islands. Seagrass is protected inside aquatic preserves, and FDEP warns that damage to seagrass can bring a fine of up to $1,000. Hillsborough County ELAPP photographs held by USF Digital Commons show Cockroach Bay Youth Environmental Stewardship Camp members carrying large pipes for an artificial reef on January 16, 1997.

Dense mangroves make the water the practical way in, and FDEP notes that many areas are too shallow for boats, leaving paddlecraft the best option for the most remote parts of Cockroach Bay. FDEP names the Cockroach Bay Road Boat Ramp as direct access, with boats also launching to the north at the E.G. Simmons Park Boat Ramp and at the smaller Domino Boat Ramp south of Ruskin, which has limited depth.

The FWC Boating and Angling Guide to Tampa Bay places the Cockroach Bay ramp at the end of Cockroach Bay Road in Ruskin, managed by Hillsborough County Parks, Recreation and Conservation, with one paved lane; the guide's survey date is February 2010. FDEP sets no hours for the preserve itself, charges no preserve fee, and leaves hours and fees to the agencies running each access point.