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Fledgling seabirds in Hawaii are easy prey for tiger sharks

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Fledgling seabirds in Hawaii are easy prey for tiger sharks


A tiger shark lunges out of the water to grab a young albatross. A new study has revealed that fledgling seabirds attract tiger sharks during the summer at Hawaii’s French Frigate Shoals. Image via Joe Spring/ NOAA/ University of Hawaii Manoa.

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  • Tiger sharks gather around Hawaii’s French Frigate Shoals in summer to prey on newly fledged seabirds, a new study has revealed.
  • The influx of tiger sharks pushes smaller shark species to change where and how they hunt.
  • Seasonal seabird movements strongly influence the balance of the entire local shark ecosystem.

When seabirds fledge, northwestern Hawaii shark ecosystems are disrupted

There are several shark species that patrol the waters of the French Frigate Shoals atoll in northwestern Hawaii. In December 2025, scientists reported that the population of tiger sharks surges during the summer in some areas of the atoll. That’s because those sharks are opportunistically preying on newly fledged seabirds, primarily albatross chicks. Moreover, that high seasonal influx of tiger sharks forces smaller sharks in those waters to change the way they use their habitat.

Chloé Blandino, at the Hawaii Institute of Marine Biology Shark Lab, is the lead author of the paper on this study. She said in a statement:

We discovered that tiger sharks gather around small islands in summer to hunt fledgling seabirds, which, in turn, forces other smaller sharks to adjust their habitat use. It’s a clear example of how a seasonal food source can influence habitat use by an entire predator community.

The researchers published their findings in the peer-reviewed journal Ecosphere on December 2, 2025.

Tiger sharks go after young seabirds

The French Frigate Shoals in northwestern Hawaii is a crescent-shaped barrier reef with small sandy islands. These tiny islands provide critical habitat for seabirds, green sea turtles, and Hawaiian monk seals. The seabirds include species like albatrosses, tropicbirds and terns.

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Blue ocean with a crescent-shaped atoll and some clouds.
This image of the French Frigate Shoals in the northwestern Hawaiian Islands was captured by an astronaut in 2003. It shows the crescent shaped reef hugging a lagoon with small sandy islands. Image via NASA.

During the summer, tiger sharks converge in the atoll waters to prey on fledgling seabirds. These young birds, which hatched just months earlier, are just learning to fly. As a result, they have not yet become adept at avoiding predators.

Tracking shark behavior

The researchers targeted three species known to frequent the atoll waters: tiger sharks (Galeocerdo cuvier), Galapagos sharks (Carcharhinus galapagensis), and gray reef sharks (Carcharhinus amblyrhynchos).

They surgically inserted acoustic transmitters in the sharks, each one emitting a unique coded signal. Their work followed careful animal handling protocols that University of Hawaii researchers developed to minimize harm to the sharks.

In addition, the researchers installed underwater receivers to pick up sounds from each shark’s transmitter. These receivers were placed in habitats occupied by the sharks: near coral reefs, as well as in deep and shallow lagoon areas. As a result, when a shark swam near a receiver, the signal from its transmitter was picked up, recording a timestamped location for the animal. This allowed the scientists to track each shark’s movement.

Blue ocean with a crescent-shaped atoll. It is marked with blue, yellow, and red dots within circles and oblongs of dotted lines.
Another image of the French Frigate Shoals, marked with the locations of acoustic receivers. Yellow dots indicate the locations of receivers in the shallow lagoon area and near small sandy islands. Blue dots are for receivers at the deep parts of the lagoon. And red dots are receivers near the coral reef. The dotted boundaries are data analysis regions used by the scientists. Image via Blandino, C. A., et al./ Ecosphere (CC BY 4.0)

Extra influx of tiger sharks affects other sharks

For two years, the scientists tracked 128 sharks at the French Frigate Shoals. Their data revealed interesting information about the sharks’ movements.

They found that tiger sharks are more abundant in the shallow lagoon of the atoll in summer, around the time that albatross chicks are fledging. They were taking advantage of easy prey since the chicks were not yet adept fliers.

Moreover, the summer influx of tiger sharks also affected the dynamics of the atoll’s shark community. Grey reef sharks, which are smaller than tiger sharks, moved out of the lagoon areas occupied by tiger sharks. They retreated to waters near the reef to primarily hunt fish. Meanwhile, Galapagos sharks changed the timing of their hunts in some places. They also preyed on monk seal pups, avoiding albatross chicks.

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Towards the end of summer, surviving fledgling seabirds, along with their parents, dispersed farther out to sea. With no more easy prey to take down, most tiger sharks moved out of the shallow lagoon, and the other sharks returned to their usual ecological niches.

Seabirds have a big impact on shark population

Carl Meyer, also at the Hawaii Institute of Marine Biology Shark Lab, is a paper co-author. He and his colleagues noted that if the birds lost their habitat to adverse weather, it would have a significant effect on the shark community, the Hawaiian monk seals, and of course, the seabirds themselves.

Two seals on a beach looking at two sharks in shallow water.
Two Hawaiian monk seal pups watching two Galapagos sharks swimming in shallow water at Trig Island in the French Frigate Shoals. Image via Carl Meyer/ University of Hawaii Manoa.

Meyer commented:

This study highlights the far-reaching impact of seabirds, showing they can shape the movements of top predators like tiger sharks, which then ripple through the entire food web. Understanding these predator-prey links is crucial for managing Hawaii’s marine ecosystems.

Bottom line: When seabirds fledge at the French Frigate Shoals atoll of northwestern Hawaii, tiger sharks move in to prey on the fledgling seabirds, disrupting shark populations in the area.

Source: Seabirds mediate intraguild and competitive interactions in a shark community

Via University of Hawaii Manoa

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Read more: Teenage Greenland sharks’ hangout spot revealed in new study

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Hawaii County Surf Forecast for April 27, 2026 | Big Island Now

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Hawaii County Surf Forecast for April 27, 2026 | Big Island Now


Forecast for Big Island Windward and Southeast


Shores Tonight Monday
Surf Surf
PM AM AM PM
North Facing 2-4 2-4 1-3 1-3
East Facing 2-4 2-4 3-5 3-5
South Facing 2-4 2-4 2-4 2-4
TONIGHT
Weather Mostly cloudy. Occasional showers.
Low Temperature In the upper 60s.
Winds Northeast winds 5 to 10 mph, becoming
northwest after midnight.
Tides
Hilo Bay Low 0.5 feet 06:03 PM HST.
High 2.0 feet 12:18 AM HST.
MONDAY
Weather Partly sunny. Scattered showers.
High Temperature In the lower 80s.
Winds Northeast winds 5 to 10 mph.
Tides
Hilo Bay Low 0.0 feet 06:52 AM HST.
High 1.8 feet 01:18 PM HST.
Sunrise 5:54 AM HST.
Sunset 6:42 PM HST.

Forecast for Big Island Leeward


Shores Tonight Monday
Surf Surf
PM AM AM PM
West Facing 2-4 2-4 2-4 2-4
South Facing 2-4 2-4 2-4 2-4
TONIGHT
Weather Mostly sunny until 6 PM, then mostly
cloudy until 12 AM, then partly cloudy.
Isolated showers.
Low Temperature In the upper 60s.
Winds Light and variable winds.
Tides
Kona Low 0.3 feet 06:40 PM HST.
High 1.6 feet 12:56 AM HST.
Kawaihae Low 0.4 feet 07:01 PM HST.
High 1.6 feet 01:02 AM HST.
MONDAY
Weather Mostly sunny. Isolated showers.
High Temperature In the lower 80s.
Winds Southwest winds around 5 mph.
Tides
Kona Low 0.0 feet 07:29 AM HST.
High 1.5 feet 01:56 PM HST.
Kawaihae Low -0.1 feet 07:40 AM HST.
High 1.6 feet 02:12 PM HST.
Sunrise 5:58 AM HST.
Sunset 6:46 PM HST.

Surf along north facing shores will begin to gradually ease tonight into the first half of the week. An upward trend is expected during the second half of the week as a new northwest swell arrives. This may be followed by a larger northwest swell Friday/Saturday, with surf heights nearing the advisory levels for exposed north and west facing shores.

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Surf along south facing shores will remain somewhat inconsistent as a southwest swell peaks this evening/tonight. This will be followed by a gradual downward trend by Monday. Another small south-southwest pulse may arrive next weekend from activity within our swell window east of New Zealand.

Surf along east facing shores will remain relatively small and choppy, though a brief strengthening of the trade winds tomorrow could lead to a small bump in surf.

ARTICLE CONTINUES BELOW AD
ARTICLE CONTINUES BELOW AD

NORTH EAST

am        pm  

Surf: Minimal (ankle high or less) surf.

Conditions: Semi choppy with ESE winds 5-10mph in the morning increasing to 10-15mph in the afternoon.

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NORTH WEST

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am        pm  

Surf: Minimal (ankle high or less) surf.

Conditions: Clean in the morning with ESE winds less than 5mph. Bumpy/semi bumpy conditions for the afternoon with the winds shifting W 5-10mph.

WEST

am        pm  

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Surf: Minimal (ankle high or less) surf.

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Conditions: Light sideshore texture in the morning with NNW winds 5-10mph. Bumpy/semi bumpy conditions for the afternoon with the winds shifting to the WNW.

SOUTH EAST

am        pm  

Surf: Minimal (ankle high or less) surf.

Conditions: Sideshore texture/chop with NE winds 10-15mph.

Data Courtesy of NOAA.gov and SwellInfo.com

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County launches coastal management education tool – West Hawaii Today

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Hawaii County Surf Forecast for April 26, 2026 | Big Island Now

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Hawaii County Surf Forecast for April 26, 2026 | Big Island Now


Forecast for Big Island Windward and Southeast


Shores Tonight Sunday
Surf Surf
PM AM AM PM
North Facing 3-5 2-4 2-4 2-4
East Facing 3-5 2-4 2-4 2-4
South Facing 1-3 1-3 1-3 1-3
TONIGHT
Weather Mostly sunny until 6 PM, then mostly
cloudy. Numerous showers.
Low Temperature In the upper 60s.
Winds Northeast winds 5 to 10 mph, becoming
northwest after midnight.
Tides
Hilo Bay Low 0.4 feet 04:55 PM HST.
High 2.1 feet 11:39 PM HST.
SUNDAY
Weather Partly sunny. Scattered showers.
High Temperature In the lower 80s.
Winds Northeast winds 5 to 10 mph.
Tides
Hilo Bay Low 0.1 feet 06:30 AM HST.
High 1.5 feet 12:37 PM HST.
Sunrise 5:54 AM HST.
Sunset 6:42 PM HST.

Forecast for Big Island Leeward


Shores Tonight Sunday
Surf Surf
PM AM AM PM
West Facing 2-4 2-4 2-4 2-4
South Facing 1-3 1-3 2-4 2-4
TONIGHT
Weather Mostly sunny until 6 PM, then mostly
cloudy until 12 AM, then partly cloudy.
Isolated showers.
Low Temperature In the upper 60s.
Winds Southwest winds around 5 mph, becoming
east in the evening, then becoming
north after midnight.
Tides
Kona Low 0.3 feet 05:32 PM HST.
High 1.7 feet 12:17 AM HST.
Kawaihae Low 0.4 feet 05:43 PM HST.
High 1.7 feet 12:14 AM HST.
SUNDAY
Weather Mostly sunny. Isolated showers.
High Temperature In the lower 80s.
Winds Southwest winds around 5 mph.
Tides
Kona Low 0.1 feet 07:07 AM HST.
High 1.2 feet 01:15 PM HST.
Kawaihae Low -0.1 feet 07:15 AM HST.
High 1.3 feet 01:33 PM HST.
Sunrise 5:58 AM HST.
Sunset 6:46 PM HST.

A medium-period northwest swell peaks tonight into Sunday, producing small to moderate surf for north and west-facing shores, before gradually declining through early next week. A hurricane-force low tracking across the Aleutian Islands tonight should send a moderate northwest swell towards Hawaii around the middle of next week.

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Short-period northeasterly energy is beginning to decrease this afternoon, which will keep below average surf along eastern exposures for the first half of next week due to the lack of any strong trade wind activity. Locally strong trade winds could return during the latter half of next week, which could bring rough and choppy surf with near normal wave heights.

Small background energy from the west will continue to linger through today and fade out on Sunday. A small southwest bump from the Tasman Sea is expected to slowly fill in tonight and peak on Sunday. No significant south swell is expected through the first half of next week. A fetch of gales passing east of New Zealand today could produce a small south-southwest swell for next weekend.

ARTICLE CONTINUES BELOW AD
ARTICLE CONTINUES BELOW AD

NORTH EAST

am        pm  

Surf: Minimal (ankle high or less) surf.

Conditions: Semi choppy with ESE winds 5-10mph in the morning increasing to 10-15mph in the afternoon.

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NORTH WEST

ARTICLE CONTINUES BELOW AD

am        pm  

Surf: Minimal (ankle high or less) surf.

Conditions: Clean in the morning with ESE winds less than 5mph. Bumpy/semi bumpy conditions for the afternoon with the winds shifting W 5-10mph.

WEST

am        pm  

ARTICLE CONTINUES BELOW AD

Surf: Minimal (ankle high or less) surf.

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Conditions: Light sideshore texture in the morning with NNW winds 5-10mph. Bumpy/semi bumpy conditions for the afternoon with the winds shifting to the WNW.

SOUTH EAST

am        pm  

Surf: Minimal (ankle high or less) surf.

Conditions: Sideshore texture/chop with NE winds 10-15mph.

Data Courtesy of NOAA.gov and SwellInfo.com

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