No vacancy on float for harbor seals

The rain ended, the sun came out, and so did the harbor seals at Alameda Point.  So many of them came out of the water to warm up on their new float on January 5, hardly any of the structure was visible.  The number has many observers asking for a second float.

Seventy harbor seals rest on new float at Alameda Point on January 5, 2017.
Seventy harbor seals rest on new float at Alameda Point on January 5, 2017.

The regional ferry agency installed the new float after removing an old Navy dock used by the seals, in order to make way for a ferry maintenance facility.

“I nearly keeled over when I saw the platform,” said Lisa Haderlie Baker, harbor seal monitor and Alameda resident.  “So many seals packed cheek by jowl, literally, that I had to count them four times using binoculars to make sure there were 60 of them, at least, basking in the sun, which I knew had to be close to a record.  It was a tremendous thrill.”  Continue reading “No vacancy on float for harbor seals”

Ospreys nest successfully in 2016 at Alameda Point

Location, location, location! But for a fenced-off dilapidated navigation light stand on a jetty at the Seaplane Lagoon, ospreys would not have had a successful nesting season this year.

In late August two adult ospreys took flight from their Seaplane Lagoon perch for parts unknown with two healthy offspring. It was a welcome sight because for the past three years a series of frustrating avian soap operas featuring other ospreys and unwanted nesting attempts aboard the maritime ship Admiral Callaghan were marked with failure. Previously in 2012 they had raised one chick, the only other recorded case of osprey reproduction at Alameda Point.

Two young ospreys on June 8, 2016, at Alameda Point Seaplane Lagoon.
Two young ospreys on June 8, 2016, at Alameda Point Seaplane Lagoon.

Continue reading “Ospreys nest successfully in 2016 at Alameda Point”

Harbor seals adapting to new float

A new concrete float for harbor seals was delivered to Alameda Point on June 22. It is the first-of-its-kind on the West Coast. With seals starting to use the new platform, a milestone has been reached culminating two-and-a-half years of citizen advocacy to maintain a resting site for harbor seals at Alameda Point. A ferry maintenance facility is slated to begin construction this summer where the seals have been finding solitude for over a decade. The new float will be anchored 300 yards away to the east.

Harbor seals on new float Alameda

In an effort to acclimate the seals to their new float and surroundings, the float is being moved in stages to its permanent location. It will be anchored a hundred yards offshore from the Bay Trail near the soccer field on West Hornet Avenue. Continue reading “Harbor seals adapting to new float”

Marine ecosystem thrives at Alameda Point

Conservation of wildlife isn’t just important at Crab Cove 

Visitors flock to Crab Cove, a State Marine Conservation Area, to learn about and experience the Bay’s sea dwellers. The educational lessons at the Crab Cove Visitor Center are equally relevant throughout the waterway south of the USS Hornet at Alameda Point where even more creatures thrive in relative obscurity.

The area encompasses an interconnected web of vegetation, birds, seals, fish, mollusks, crustaceans and worms. Ghost shrimp, bat rays, leopard sharks, striped crabs, mussels, California sea hares and fish with light-emitting diodes are just a sampling. A 36-foot-wide rock wall, known as a breakwater and built by the Navy in 1945, forms the mile-long southern boundary.

Ghost shrimp at Breakwater Beach, Alameda Point. Red spots on shrimp are baby shrimp. Click on photo to enlarge.
Ghost shrimp at Breakwater Beach, Alameda Point. Red spots on shrimp are baby shrimp. Click on photo to enlarge.

Ghost shrimp are seldom seen, since they spend most of their lives in tunnels constantly digging and filtering the sandy mud for nutrients. But the evidence of their presence is plain to see during low tide at the mudflat west of the Encinal Boat Ramp. Thousands of small mud mounds dotting the landscape have an opening in the center leading down into the shrimp burrow.

Mudflat at Breakwater Beach, Alameda Point, during low tide showing shrimp burrows.
Mudflat at Breakwater Beach, Alameda Point, during low tide showing shrimp burrows.

The shrimps’ perpetual mining and aeration of the mud makes the environment attractive to other species as well, such as the arrow goby. These tiny fish are only a few inches long and almost completely transparent. They share the burrows with the shrimp. At low tide they can be seen darting around in shallow pools of water in the sand. Occasionally least terns dive to grab a goby.

Two arrow gobies at Breakwater Beach, Alameda Point. The gobies take shelter inside of ghost shrimp tunnels and also benefit from the shrimps' feeding activities that release food morsels the fish can eat.
Two arrow gobies at Breakwater Beach, Alameda Point. The gobies take shelter inside of ghost shrimp tunnels and also benefit from the shrimps’ feeding activities that release food morsels the fish can eat.

Lugworm at Breakwater Beach, Alameda PointA neighbor of the shrimp and gobies is the lugworm or sandworm. They, too, are seldom seen, but at low tide their ropey casings of excavated sand and mud are a clear sign of their presence. Another sign of their presence in recent weeks are the almost clear egg sacs. At low tide they look like deflated balloons that washed ashore. But when submersed in water, it becomes apparent that the egg sacs are tethered to the worms’ tunnels. The jelly sac keeps the eggs moist at low tide.

Lugworm egg sacs on Breakwater Beach, Alameda Point.
Lugworm egg sacs on Breakwater Beach, Alameda Point.

Another seldom seen creature is the foot-long California sea hare or sea slug. Their brownish color and slow movement makes them difficult to spot, even when they venture among the rocks near the water surface. During egg-laying season, a clue to their presence is the large bright yellow clumps of eggs deposited on the rocks, which look like angel hair pasta. 

CA sea hare, or sea slug, foraging for food on rocky shoreline next to Bay Trail.
CA sea hare, or sea slug, foraging for food on rocky shoreline next to Bay Trail.

Sea vegetation serves as an anchor for herring eggs. Some eggs are churned up by tides and currents during the prolific herring-spawning season and eaten by birds.

Gull with herring eggs attached to shafts of vegetation it retrieved from just below the water surface in Alameda Point harbor.
Gull with herring eggs attached to shafts of vegetation it retrieved from just below the water surface in Alameda Point harbor.

Algae and vegetation on rocks in the tidal zone serve as food for striped crabs, always busy picking away. But crabs will quickly move under a rock if they spot a visitor with one of their eyes that can be raised up out of the socket.

Striped crab on breakwater at Alameda Point.
Striped crab on breakwater at Alameda Point.

Armies of kelp flies walk – not fly – along the waterline on the beach during warm weather waiting for kelp to wash up so they can lay eggs.

Kelp flies on Breakwater Beach, Alameda Point.
Kelp flies on Breakwater Beach, Alameda Point.

Small fish, such as the jack smelt, provide food for the diving California least terns.  Just about any size fish is prey for the California brown pelicans that hang out by the thousands on the section of breakwater surrounded by water known as Breakwater Island.  Fellow marine birds the double-crested cormorants dive deep, chasing down prey by paddling their webbed feet.  Mussels are a delicacy for gulls, which can often be seen hovering and dropping mussels on rocks and pavement to crack open the shell.

Mussels and barnacles on the breakwater at Breakwater Beach, Alameda Point.
Mussels and barnacles on the breakwater at Breakwater Beach, Alameda Point.

The strangest fish to appear in the channel is the plainfin midshipman. It can create its own light in the deep waters it inhabits during most of the year. Their skin is laced with hundreds of bioluminescent photophores that can help it attract prey, as well as emitting light that matches surrounding water to make it difficult for predators to see.

Cormorant holding plainfin midshipman that it retrieved by diving in the Alameda Point Channel. Dotted lines on underbelly of fish are light-emitting photophores. These fish lay eggs among shoreline rocks and their young are capable of breathing air during low tide before maturing and swimming away. Due to lack of research, it is unknown whether plainfin midshipman lay eggs at Alameda Point. Other smaller and easier to swallow plainfin midshipman were caught by this cormorant.
Cormorant holding plainfin midshipman that it retrieved by diving in the Alameda Point Channel. Dotted lines on underbelly of fish are light-emitting photophores. These fish lay eggs among shoreline rocks and their young are capable of breathing air during low tide before maturing and swimming away. Due to lack of research, it is unknown whether plainfin midshipman lay eggs at Alameda Point. Other smaller and easier to swallow plainfin midshipman were caught by this cormorant.

The leopard shark with its large leopard-like brown markings can grow to seven feet in length but is harmless to humans. These fish forage for food in the shallow intertidal zone going after crabs, shrimp, worms, other fish and fish eggs.

Leopard shark next to breakwater at Alameda Point.
Leopard shark next to breakwater at Alameda Point.

A gracefully beautiful fish and a regular at Alameda Point is the bat ray, which feeds along the bottom but can occasionally be seen swimming just below the surface.

Bat ray near Bay Trail at Alameda Point.
Bat ray near Bay Trail at Alameda Point.

A moon jellyfish was recently spotted in Alameda Point waters, drifting along near the surface.

Moon jellyfish drifting at the gap in the breakwater at Alameda Point.
Moon jellyfish drifting at the gap in the breakwater at Alameda Point.

Harbor seals, representing marine mammals, round out the marine life roster. Alameda Point hosts the only harbor seal haul-out in the East Bay between Yerba Buena Island and Fremont.

Harbor seals at Alameda Point at sunrise.
Harbor seals at Alameda Point at sunrise.

Originally published in the Alameda Sun.

More photos of Alameda Point marine life, with map

Ghost shrimp with eggs at Breakwater Beach, Alameda Point.
Ghost shrimp with eggs at Breakwater Beach, Alameda Point.
Red objects on ghost shrimp are baby ghost shrimp, at Breakwater Beach, Alameda Point.
Red objects on ghost shrimp are baby ghost shrimp, at Breakwater Beach, Alameda Point.
CA sea hare, or sea slug, foraging along rocky shoreline next to Bay Trail at Alameda Point.
CA sea hare, or sea slug, foraging along rocky shoreline next to Bay Trail at Alameda Point.
CA sea hare (rear view) with yellow strands of eggs recently deposited on the breakwater.
CA sea hare (rear view) with yellow strands of eggs recently deposited on the breakwater.
Closeup showing individual CA sea hare eggs at Alameda Point.
Closeup showing individual CA sea hare eggs at Alameda Point.
School of anchovies at shoreline next to Bay Trail.
School of anchovies at shoreline next to Bay Trail.
Tube worm on Breakwater Beach, Alameda Point.
Tube worm on Breakwater Beach, Alameda Point.
Jack smelt caught by fisherman at Alameda Point breakwater to use as bait.
Jack smelt caught by fisherman at Alameda Point breakwater to use as bait.
Two striped crabs eating vegetation on the breakwater at Alameda Point.
Two striped crabs eating vegetation on the breakwater at Alameda Point.

Alameda Point waterway

Ferry agency, volunteers help the least terns

Three thousand tons of sand was added to the nesting grounds for the least terns at Alameda Point in late February and early March. In the weeks that followed, volunteers from St. George Spirits and the Boy Scouts and Cub Scouts came out to help make the site ready for the arrival of the terns in mid-April.

Sand being delivered to the least tern nesting grounds at Alameda Point on February 25, 2016. Bay Bridge in the background.
Sand being delivered to the least tern nesting grounds at Alameda Point on February 25, 2016. Bay Bridge in the background.

The Water Emergency Transportation Authority (WETA) paid for enough sand to cover half of the 9.6-acre nesting area with three inches of sand, as well as for grading. The weeklong delivery of sand was a conservation mitigation requirement for the impact that WETA’s new ferry maintenance facility will have on the terns’ feeding area. As many as 12 ferries will make up to four passes per weekday through the Alameda Point Channel where the terns frequently dive for small fish.

Wind and water erosion take their toll on the sand substrate lying atop old airfield taxiway pavement, requiring periodic replenishment. This latest delivery of Angel Island coarse sand has built up the sand depth on much of the site to the point that it’s starting to feel like a real beach underfoot. Beaches are the traditional nesting habitat for terns.

In March, virtually all of the employees of nearby St. George Spirits showed up on a rainy Sunday morning to help distribute cinder block grid markers and clay tile chick shelters throughout the site. The high-spirited and determined crew trudged through puddles of water determined to get the job done regardless of how wet they got. Some of the volunteers worked in the old Quonset hut repainting and numbering the plaster markers that the Fish and Wildlife Service uses to identify each nest. Others re-stenciled cinder blocks.

Employees of St. George Spirits volunteering on March 13, 2016.
Employees of St. George Spirits volunteering on March 13, 2016.

The cinder blocks and the plaster markers allow for systematic data collection on nesting success. The blocks and markers were removed prior to the sand delivery and grading work.

In April, Alameda Boy Scouts of Troop 73 joined the Cub Scouts from Pack 1015 for the final preparations for the least tern arrival. “Overall, 25 youth from 4th grade to 12th grade and 15 parents joined this final chilly work day putting out oyster shells, flattening the area after a week of rain and pulling the last of the weeds,” said Dorinda von Stroheim, Webelos Den Leader Pack 1015. “The kids loved placing the shells and took extra care to make sure all the shells were evenly distributed.” The scouts were supposed to get pizza delivered at noon, but they hustled through their assignments so quickly that the pizza parlor was not even open yet. They accepted a rain check from the Audubon Society.

Boy Scouts and Cub Scouts, some holding up oyster shells, at the least tern nesting site April 10, 2016.
Boy Scouts and Cub Scouts, some holding up oyster shells, at the least tern nesting site April 10, 2016.

The least terns, an endangered species, have enjoyed phenomenal success on the old airfield at Alameda Point. Pushed to the brink of extinction by human encroachment on their traditional Southern California coastal nesting areas, the terns began taking up residence on a number of military bases in California during the past four decades. With early and continued stewardship by the Navy through 2014, and the addition of volunteers after the base closed, the Alameda Point colony went from a few nests to over 300 today.

Adult least tern with chick during 2014 nesting season at Alameda Point. Photographed through chain link fence.
Adult least tern with chick during 2014 nesting season at Alameda Point. Photographed through chain link fence.

During the 2015 nesting season, the Alameda Point terns were the top performers statewide, both in terms of the total number of fledglings produced, and the key data point — ratio of fledglings per nest — according to recently released data.

The public is invited to see the terns during the annual “Return of the Terns” event on June 18. Tours by bus leave from the Crab Cove Visitor Center after an educational presentation. Reservations are required for one of the three tours via the visitor center, or the East Bay Regional Park District’s website https://apm.activecommunities.com/ebparks using the search keyword “terns.”

Originally published in the Alameda Sun.

Longtime volunteer Frank Delfino with a fresh batch of wooden shelters that he made for the tern chicks to use for shelter.
Longtime volunteer Frank Delfino with a fresh batch of wooden shelters that he made for the tern chicks to use for shelter.
Grading the 3,000 tons of new sand on March 9, 2016, at Alameda Point least tern site.
Grading the 3,000 tons of new sand on March 9, 2016, at Alameda Point least tern site.

Harbor seal dock, ferry depot plans on track

The Water Emergency Transportation Authority (WETA) is aiming for the delivery of a new dock for harbor seals at Alameda Point as early as April, ahead of the start of construction of its new ferry maintenance facility this summer.

Harbor seals on old dock

Because the maintenance facility’s new berthing dock would displace the seals’ current resting spot, a provision was approved for a new harbor seal dock as a condition for permitting the new facility. WETA, the city council, and the Bay Conservation and Development Commission (BCDC) approved the provision at the urging of community activists.

WETA issued design specifications for its 12-berth maintenance facility and administrative offices to prospective contractors in December. It expects to award the contract on March 31, with work commencing as soon as May 6. The estimated cost is pegged at $45 million, $9 million of which is for design work and the remaining $36 million going for construction, according to Chad Mason, senior planner at WETA. Funding for the project is coming from federal, state, and regional funds.

The facility will include a 70-foot-tall four-story building and is expected to be complete in 2018.

The project will also fund other benefits, among them, a new water line from Main Street, park enhancements, and sand for the least tern nesting area on the airfield.

WETA artist's drawing - Alameda Point

WETA will construct a shoreline viewing terrace, bicycle parking, interpretive signage, improved lighting and landscaping, and seating on an adjacent half-acre of parkland on West Hornet Avenue.

WETA will also be providing some assistance for the California least terns, an endangered bird species that nests at Alameda Point and dives for fish in surrounding waters. As a mitigation for the impacts of the new ferry traffic on the terns’ foraging waters, WETA will be delivering enough truckloads of sand to the terns’ nesting area on the airfield in February to add a few inches of depth. Erosion of the 9.6-acre beach-like nesting landscape necessitates periodic replenishment.

The replacement harbor seal dock, also referred to as a haul-out, will be the first time such a structure has been built on San Francisco Bay specifically to retain or attract harbor seals. It will be located a short distance to the east of the old dock. Time will tell whether this experimental effort is successful.

Young harbor seals Alameda Point Dec. 30, 2015

“Meeting the permitting requirements for the new harbor seal haul-out is underway,” said Mason. BCDC is the state permitting agency for all Bay shoreline and in-water projects. It requires assurances from other agencies that the harbor seal dock does not introduce any unwanted environmental impacts before granting approval.

“With the help of the environmental consulting firm Dudek, the harbor seal haul-out is on a fast-track approval timeline,” said Mason. “The only regulatory delay is due to the herring spawning season. Regulations require that the pilings for the new haul-out be installed after the end of the herring spawning season in late March of 2016.”

Harbor seals near the old dock in December 2015.
Harbor seals near the old dock in December 2015.

“We are currently reviewing two options for providing the new harbor seal haul-out: Build a new one from scratch, or modify an existing mobile dock if we can find one that meets our needs,” said Mason. “We hope to issue the contract for the haul-out in January.” WETA will be responsible for constructing, maintaining and replacing the harbor seal dock when necessary for the 60-year term of its lease.

WETA has been working with a citizen advisory group of local harbor seal advocates who spearheaded the effort for the new haul-out. The group gained the support of the Sierra Club and the Audubon Society. The location for the new seal dock was chosen with the help of marine mammal expert Dr. Jim Harvey, Director of California State Universities’ Moss Landing Marine Laboratories.

Alameda Point south with harbor seal haul-out

This winter, the seals favor the afternoon for getting out of the water. Their numbers can vary from a dozen to a recent high of over three dozen. It is the only haul-out site in the East Bay between Yerba Buena Island and the marshlands of Fremont and Newark near the Dumbarton Bridge, both of which require watercraft for public viewing access. The seals at Alameda Point can be viewed from the Bay Trail.

Originally published in the Alameda Sun.

Additional photos and video

Harbor seals using old plank for hauling out.
Harbor seals using old plank for hauling out.
Harbor seal near old dock in December 2015.
Harbor seal near old dock in December 2015.
Two harbor seals diving together near the old dock in December 2015.
Two harbor seals diving together near the old dock in December 2015.

Brown pelicans display beauty during trying times

About 100 California Brown Pelicans made an unusual appearance on the old wooden dock on the south side of Alameda Point near the U.S.S. Hornet on December 23. The visit provided a rare close-up view of this colorful and iconic bird, but also a reminder of their struggle to survive as a species. Only one of the pelicans could be identified as a one- or two-year-old.

Brown Pelicans resting on old recreational boating dock on south side of Alameda Point in December.
Brown Pelicans resting on old recreational boating dock on south side of Alameda Point in December.

During the past four years, the breeding rate for California Brown Pelicans has been dismal. This recent trend has been directly attributable to the dwindling supply of sardines along the California coast, according to a Brown Pelican status report issued in October by the Washington State Department of Fish and Wildlife. The sardine population has dropped so low that in April of 2015, the agency responsible for managing Pacific Coast fisheries banned commercial fishing of sardines until the end of June 2016.

In May, the U.S. Fish and Wildlife Service urged the same agency to consider additional management measures to stave off a decline in northern anchovy, another important food source for pelicans and other marine life.

California brown pelicans resting on Alameda Point dock

Brown Pelicans were removed from the federal endangered species list in 2009 with great fanfare after recovering from the devastating effects of the agricultural pesticide DDT on their eggs. But they no sooner recovered from chemical contamination than they fell victim to a plunge in food supply.

“Although most essential nesting and roosting habitat throughout the subspecies’ range is protected, the California Brown Pelican has experienced unusual mortality events and a multi-year decline in breeding success since delisting, both of which appear to be due to the lack of adequate forage,” wrote the U.S. Fish and Wildlife Service to the Pacific Fishery Management Council on May 14, 2015.

Brown pelicans roosting on the dock

About 10 percent of California Brown Pelicans nest on two islands in Channel Islands National Park off the coast of Southern California. The remainder nest and rear their young off the western coast of Mexico.

The University of California at Davis and the Mexican national conservation agency conducted a study of the 2014 nesting season off the coast of Mexico. The U.C. Davis news summary of the study results stated, “The scientists found that this year, areas that typically host hundreds or thousands of nesting pairs held only a few hundred at most, and in some cases zero nesting pairs.” Co-author of the study, U.C. Davis wildlife biologist Dan Anderson, is quoted in the story saying, “That’s what we call a failure, a bust. The bottom dropped out.” Anderson has been monitoring Brown Pelicans for 46 years.

Brown Pelicans soaking up the sun during a rare visit to an old dock on Alameda Point's south shore.
Brown Pelicans soaking up the sun during a rare visit to an old dock on Alameda Point’s south shore.

Breeding normally begins in January. Whether the pelicans currently at Alameda Point will make the journey south is yet to be seen.

Breakwater Island along the south side of the Alameda Point Channel serves as the most popular resting site for Brown Pelicans on San Francisco Bay during the warmer months.

Immature (1 or 2 years old) Brown Pelican with all-brown head and neck, the only one spotted among about 100 pelicans on the dock on December 23, 2015.
Immature (1 or 2 years old) Brown Pelican with all-brown head and neck, the only one spotted among about 100 pelicans on the dock on December 23, 2015.

Immature Brown Pelicans are distinguishable by being entirely brown, except for their whitish underbelly.  By their third year, the neck becomes white and the head yellow.  During breeding season, the neck of adults becomes dark chestnut and the pouch under their bill becomes red. 

Reprinted on Golden Gate Birder, Golden Gate Audubon Society’s blog.

Featured on Bay Nature’s Nature News.

Further reading:

“Periodic Status Review for the Brown Pelican,” October 2015, State of Washington Department of Fish and Wildlife.

“Failure to launch:  California brown pelicans’ breeding rate dismal,” June 2, 2014, UC Davis News and Information.

“Letter from U.S. Fish and Wildlife Service to Pacific Fishery Management Council,” May 14, 2015.

Additional photos and video from December 23, 2015, Alameda Point:

California brown pelicans in breeding plumage at Alameda Point

California brown pelicans huddled on the dock

California brown pelican at Alameda Point

California brown pelicans in breeding plumage, Dec. 23, 2015, Alameda Point

Brown pelican stretching at Alameda Point