Tuesday, November 1, 2016

Seagrasses - An Important Natural Community

Common Household Items
Become Seagrass Metaphors
by Tim Marshall , OPS Ranger

Seagrasses Metaphors:
Seagrasses are “air conditioners”
Seagrasses are “coffee filters”
Seagrasses are “Rolaids”
Seagrasses are “carpeting”
Seagrasses are “pillows”
Seagrasses are “cereal”
Seagrasses are “nurseries”

How So?
Seagrasses are flowering plants that live underwater. Seagrasses serve as underwater “air conditioners” because, like land plants, seagrasses produce fresh oxygen and help to remove particulate matter.

The depth at which seagrasses are found is limited by water clarity because they require light. Although seagrasses occur throughout many coastal areas of Florida, locally, they are most abundant in the Tampa Bay, and on the gulf coast they are most abundant from Tarpon Springs northward to Apalachee Bay. Seagrasses occur in protected bays and lagoons and also in places along the continental shelf in the Gulf of Mexico.

In 2003, over 2 million estimated acres of seagrasses were determined to be playing an important role as natural resources that perform many significant functions:
1) Seagrasses are coffee filters,
they help maintain water clarity by trapping fine sediments and particles with their leaves; like Rolaids, they neutralize harmful chemicals.
2) Seagrasses are carpeting, they stabilize the bottom with their roots and rhizomes in much the same way that land grasses retard soil erosion.
3) Seagrasses are pillows, in that they provide safe resting places and needed habitat for many fishes, crustaceans, and shellfish.
4) Seagrasses are morning cereal. The seagrasses and the organisms that grow on them are food for many marine animals.
5) Seagrasses are nurseries and incubators, they are nursery areas for much of Florida’s recreationally and commercially important marine life.

Your daily encounters with common household items should now serve as ready reminder of the daily duties of our seagrass beds, as they serve to benefit us all.

Lets look a little more closely. Seagrass leaves provide excellent protection for young marine animals from larger open-water predators. Some animals, such as manatees eat seagrass blades. Other animals derive nutrition from eating algae and small animals that colonize seagrass leaves. These colonizing organisms provide an additional link in the marine food chain.

Our Seagrass Species
Although approximately 52 species of marine seagrasses exist worldwide, only seven species are found in Florida waters. Four of these are widespread in Florida and extend beyond its borders. Of these, just three are commonly found in the waters surrounding Honeymoon and Caladesi Island State Parks.

Turtle grass (Thalassia testudinum) is the largest and most robust seagrass in Florida. Its ribbon like leaves are about 1/2 inch thick and up to 14 inches long. It grows in waters up to an extreme of 82.5 feet deep, and withstands salinities as low as 20 ppt. This beneficial plant actually prefers shallower water up to 33 feet, and does best in a salinity range between 25 to 40 ppt. Turtle grass is the dominant seagrass in most estuaries in Florida.

Manatee grass (Syringodium filiforme) is the second most abundant seagrass in Florida. It is readily identified by observing its unique cylindrical leaves. The leaves vary greatly in length, but can grow up to 20 inches long in some areas. Manatee Grass can withstand salinities as low as 20 ppt. It is commonly mixed with other seagrasses, or sometimes found in small patches by itself. On rare occasion, it can be found as the sole species in large meadows.

Shoal Grass (Halodule wrightii) is extremely important as a colonizer of disturbed areas where Turtle Grass and Manatee Grass cannot grow, or where scarring or other disturbances take place. It is often found in waters otherwise too shallow or too deep for other grasses to grow. Shoal grass can withstand the widest variance in water temperature, depth, and salinity factors.

Seagrass Awareness
Seagrasses stabilize the bottom sediments and help to absorb excess nutrients from land run-off. Damaging seagrass beds leads to continually re-suspended bottom sediments and nutrients that damage the quality of our waters. Seagrass communities support hundreds of species of fish at various stages of their lives. Without healthy seagrass beds, these fish populations are compromised -- as well as negatively impacting commercial and recreational fishing, further stressing our coral reefs, and affecting the food chain tto a degree as to even impact our shore birds.

There is scarring on most every seagrass bed. Damaging seagrass with boat propellers fragments the grass bed and severely restricts the movement of marine wildlife in needed habitat, creating barren areas where fish and others once flourished.

Our Impact on Seagrasses
A moment’s carelessness can quickly impair this precious resource -- a propeller scar cut into seagrass today can be around in five years or longer. Running aground costs millions of dollars each year to boaters, resulting in towing fees, propeller replacement, engine repair, and legal fines.

The shallow waters of Clearwater Harbor, St. Joseph Sound and our other area bays and estuaries pose a particular challenge - even to the most experienced boaters. Study your charts Read the waters. Know your depth and draft. Losing our seagrass means more than a few blades of grass.

American Bald Eagle

American Bald Eagle at Honeymoon Island State Park
by Tim Marshall, OPS Ranger

The 2016-17 season marks the 9th consecutive year for eagles to nest on the island.

Historically, the last known nest  reported to the south at Caladesi Island near the Scharrer homestead. Recently, documents were located indicating that the female eagle was reported to have been shot on the nest. This was according to a Clearwater Sun article and notes from Myrtle Scharrer Betz in 1935.

This new nest was the first time eagles have reestablished nesting on the island since the 1935 homestead nest.

In early May, 2016 a storm that produced a microbirst blew down the unoccupied nest. A mated pair returned to Honeymoon Island in fall of 2016 and constructed a nest in a live Slash pine nearby. They were observed mating on October 12, 2016. Apparently no eggs were produced. It is still early in the season, so it is anticipated that a successful breeding will commence soon.

Eagles may live up to 40 years. With successful fertilization, gestation begins and after 5 days the first egg is produced. Eggs are then laid 36 hours apart, Both male and female incubate. Average gestation is 35 days, with eggs hatching one at a time 36 hours apart.

Eaglets remain in nest 10 to 12 weeks. Both parents feed young. Fledglings broaden their range slightly away from the nest over a period of 4 to 8 weeks. Young become independent of parents for food at approximately 17 to 20 weeks.

Here are records from previous years:

Eagle Nesting 2015-2016
10/01/15 Adult eagles observed readying the nest, immature eagles observed in park as well.
12/24/15 2 Eaglets hatched
03/02/16 2 Eaglets fully grown and ready to fledge
05/04/16 - Eagle nest downed by storm

Eagle Nesting 2014-2015
9/7/14 -Bald Eagles first observed returned to the island, 2 adults and at least 1 juvenile, presumably last year's chick.
11/17/14 - Mating behavior recorded
12/1/14 - Eagles incubating, due to start hatching as early as January 4th 2015 (35 days average gestation)
1/9/15 - Eggs hatched
1/25/15 - Eaglets large enough to see, 2 chicks
4/1/15 - 2 Eaglets Fledged

Saturday, October 8, 2016

The Osprey

The Osprey
by Jerry Allen, FPS Volunteer

The estimated nesting population of the Osprey in the U.S in 1994 was determined by researcher Larry Houghton to be approximately 14,000 nesting pairs. Even with modern population inventory techniques, it is still difficult to make accurate nest site counts, and involves an extremely large task with researchers having to contend with budgeting and staffing limits.

Twenty percent of the U.S. Opsrey are located in New England, 20% in the Chesapeake Bay area, and 20% in Florida. The remainder are located in the northeast U.S. and some are found west of the Mississippi.

Osprey nesting in the New England and Chesapeake Bay areas migrate to the Caribbean, Central America and Northern S. America. The others east of the Mississippi migrate to Florida. Populations west of the Mississippi migrate to Mexico. Most Osprey along the GulfCoast, S. California, and S. Florida are year-round residents of those areas and do not migrate.

This includes those here on Honeymoon Island, the reason for their abundance here being the excellent habitat, nesting sites and food sources found here.

Fall migration begins in late August and September andends in mid October. Stop off points used by northern populations before migrating south include Hawk Mountain in PA, and Cape May in New Jersey, which extends south into the ocean. Many species of migratory birds congregate in these locations, and so many ornithologists, birders and casual observers gather during peak migration in order to witness the spectacle first-hand.

Hurricanes and Predators
Osprey migrating from these areas then proceed either directly over open water, or over land. Young Osprey often select the open water route, crossing long stretches of open ocean. Nearly 2/3 of the young will perish dues to storms.

While many birds build up stores of fat to live on during migration, the Osprey does not.. They hunt actively along the way, fishing as they go, sometimes carrying a “fish snack” with them. They tend to be solitary in migration, but mated pairs travel together, riding the wind currents and soaring on updrafts and thermals.

The mature birds migrate by instinct and navigate by eye, always aware of landmarks, returning to the same wintering grounds year after year. The fledglings too, will be driven by instinct, navigating by the ancestral “map” embedded within. The young that successfully manage the migration fly thousands of miles until they somehow recognize a place they have never been to before, and something within them will say “home”. Then they will settle into this ancient wintering ground, and partake inthe abundance of fish as they regain their strength after the strenuous migration. The ability to recognize a place they have never been to before is surely a fact stranger than fiction.

Winter Quarters
The return trip south takes about 1/3 the time it took tomigrate north, as they seem anxious to return to the nest and ready it for a new family. Once settled in, returning mated pairs tend their nests, and those without mates engage in courtship. Older pairs will rebuild their nest and newlyweds will work to build a new nest. Occasionally, established nests are damaged by storms, and the couple will select a new sight.

There is always the chance that the Great Horned Owl will select an Osprey nest and call it its own. The Owls leave the nestin ill repair, and badly soiled, being the “good renters” that they are.

By mid march, most wintering sites used by the Osprey that do migrate are ghost towns, barren of all but the yearling birds who continue to hone their hunting skills and gain experience. The cycle of life begins anew!

To experience the Osprey first hand, and learn more about their life history, join in on one of the Ranger-Led Osprey Trail walks, held each Saturday at the Picnic area at 11am, November through March.

Resources: Alan Poole, Biologist Larry Raymond and Stephen D. Capenteri, “The Fish Hawk Osprey”.

Friday, September 9, 2016

Mmmm, Mudflats!


By Tim Marshall, OPS Ranger

Stuck in the mud
Have you ever been stuck it the mud? What was it like? What would it be like to live in the mud?

It stinks!
Q: What's that rotten egg smell?
A: It's rotting organic matter, stuck in the mud, without oxygen to help break it down.. As things slowly decompose, methane gas is created and trapped in the mud. The methane is what smells.

All you can eat!
Q: Are mudflats an all you can eat buffet? What's on the menu?
A: Mudflats are home to thousands of species of bacteria, insects, worms, shellfish and crustaceans. Many of the burrowing animals in this habitat are filter feeders, who siphon tiny particles of food from the nutrient-rich water.

Looking for life
This place looks mostly devoid of life - a wet wasteland... Wait! - Exploring the surface of a mudflat reveals the many holes and depressions created by the animals who live and feed here.

Oh give me a home
Q: Where can an animal live in a mud flat?
A: They can live on the surface or in shallow burrows beneath the surface.

Life is tough
Q: What makes it hard to live in a mud flat?
A: Low oxygen, wind, wave action, fresh water, pollution, salinity, sun, temperature extremes, salt, difficulty moving, and few hard surfaces for attachment. Food gathering is hard work.

Where’d all this mud come from?
Q: How did this place "get here"?
A: Mudflats are created by ocean tides which erode shorelines and then drop the sediment in a new location. This buildup of sentiment causes the flat, muddy environment that gives this natural community its name.

Where can I find a mud flat?
Mudflats exist on coastal water edges, & are under water during high tide and exposed to the air during low tide. Beaches are typically not muddy but sandy, because the waves carry away the fine soluble mud. Mud settles down in calm areas, like where mangroves calm the wave action, and behind barrier islands where it is not usually wavy, but calm.

Who lives in a mudflat?
Q: Which plants and animals stick it out in the mud?
A: Most plants cannot survive in a mudflat because of the constant tides. Microscopic algae is abundant, and a few hardy plants or plants that are able to take root in mud, such as eelgrass, can also be found. Worms living in the mudflats burrow and excavate, depositing lumps of mud, leaving slime trails, or pumping water through their filter feeding systems. Worms such as the parchment worm live in lavishly lined houses, encased in comfort.

Most animals living in the mudflats burrow into the sediment to avoid being swept away by tides,  to hide from predators, and to prevent exposure to sun, heat and drying out at low tide.

Animals living in mudflats include microscopic invertebrates, mollusks, crustaceans, snails and worms. These animals are mostly filter or deposit feeders.

The tide is low
Larger animals such as shore birds like reddish egrets, willets and roseate spoonbills often feed on the mollusks, crustaceans and other invertebrates which are exposed on mudflats during low tides.

The tide is high
During high tides, dolphins, sharks, stingrays and  fish such as snook and redfish may swim into the mudflats to feed.