Coral Reef Diagnostics

Indonesia - Banda

NOAA Coral Reef Watch

Regional summary of 7 dive sites. Figures are averages across the sites that report them (n = sites with a value); each site's own page has its individual values. Part of the Indonesia - Maluku overview.

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05
Coral Reef Diagnostics
Photo: Anderson Mayfield/Coral Reef Diagnostics — Indonesia - Banda Islands: Airport (Banda Ara)
Country
Indonesia
Sites
7
each linked below
Hard coral cover (regional mean)
35% ± 11% (std. dev.)
n=7. range 16–55%
Water temp. during surveys (regional mean)
29.9°C
n = 7 of 7 sites; surveyed Apr 2018
Coral Health Index (regional mean)
4.75 / 5
n = 1 of 7 sites; 2.5 = average (above average)
Most recent water temperature record
16 Sep 2026 · Maluku
Most recent heat stress record
16 Sep 2026 · below alert level
Mean annual max degree heating weeks (DHW), last 5 years
2021–2025 · Maluku
Highest annual heat stress
in 2022 · Maluku
Severe heat-stress years
1985–2025 · 8 in the last 10 years
Heat-stress figures: NOAA Coral Reef Watch — Maluku 5-km virtual station. Each pill links its source record and carries the values behind it.
Regional summary

Banda's steep walls, draped in sponges, sea fans, and soft corals, rise to shallow terraces carpeted in Acropora or leather corals, dived in April 2018. On Gunung Api's 1988 lava flow, plate corals now cover the old lava channel almost completely, though localized bleaching was photographed there.

Heat stress

04812Week of 2023-01-01: DHW 9.7°C-weeks (Alert Level 2+: severe bleaching and significant mortality likely); SST 29.49°CWeek of 2023-01-08: DHW 9.7°C-weeks (Alert Level 2+: severe bleaching and significant mortality likely); SST 29.28°CWeek of 2023-01-15: DHW 9.4°C-weeks (Alert Level 2+: severe bleaching and significant mortality likely); SST 29.51°CWeek of 2023-01-22: DHW 8.5°C-weeks (Alert Level 2+: severe bleaching and significant mortality likely); SST 29.47°CWeek of 2023-01-29: DHW 7.0°C-weeks (Alert Level 1: significant bleaching likely); SST 29.44°CWeek of 2023-02-05: DHW 5.7°C-weeks (Alert Level 1: significant bleaching likely); SST 29.16°CWeek of 2023-02-12: DHW 4.2°C-weeks (Alert Level 1: significant bleaching likely); SST 29.16°CWeek of 2023-02-19: DHW 2.8°C-weeks (below the bleaching alert threshold); SST 29.20°CWeek of 2023-02-26: DHW 2.2°C-weeks (below the bleaching alert threshold); SST 29.35°CWeek of 2023-03-05: DHW 1.0°C-weeks (below the bleaching alert threshold); SST 29.26°CWeek of 2023-03-19: DHW 0.5°C-weeks (below the bleaching alert threshold); SST 30.23°CWeek of 2023-03-26: DHW 0.7°C-weeks (below the bleaching alert threshold); SST 30.05°CWeek of 2023-04-02: DHW 0.7°C-weeks (below the bleaching alert threshold); SST 29.57°CWeek of 2023-04-09: DHW 0.7°C-weeks (below the bleaching alert threshold); SST 29.73°CWeek of 2023-04-16: DHW 0.7°C-weeks (below the bleaching alert threshold); SST 29.91°CWeek of 2023-04-23: DHW 0.8°C-weeks (below the bleaching alert threshold); SST 29.94°CWeek of 2023-04-30: DHW 0.8°C-weeks (below the bleaching alert threshold); SST 29.72°CWeek of 2023-05-07: DHW 0.8°C-weeks (below the bleaching alert threshold); SST 29.61°CWeek of 2023-05-14: DHW 0.8°C-weeks (below the bleaching alert threshold); SST 29.36°CWeek of 2023-05-21: DHW 0.8°C-weeks (below the bleaching alert threshold); SST 29.08°CWeek of 2023-05-28: DHW 0.8°C-weeks (below the bleaching alert threshold); SST 29.08°CWeek of 2023-06-04: DHW 0.8°C-weeks (below the bleaching alert threshold); SST 29.18°CWeek of 2023-06-11: DHW 0.8°C-weeks (below the bleaching alert threshold); SST 29.01°CWeek of 2023-06-18: DHW 0.2°C-weeks (below the bleaching alert threshold); SST 28.92°CWeek of 2023-06-25: DHW 0.2°C-weeks (below the bleaching alert threshold); SST 29.04°CWeek of 2023-07-02: DHW 0.2°C-weeks (below the bleaching alert threshold); SST 29.02°CWeek of 2023-07-09: DHW 0.2°C-weeks (below the bleaching alert threshold); SST 28.67°CWeek of 2023-07-16: DHW 0.2°C-weeks (below the bleaching alert threshold); SST 28.43°CWeek of 2023-11-26: DHW 0.8°C-weeks (below the bleaching alert threshold); SST 30.45°CWeek of 2023-12-03: DHW 2.2°C-weeks (below the bleaching alert threshold); SST 30.79°CWeek of 2023-12-10: DHW 2.5°C-weeks (below the bleaching alert threshold); SST 30.29°CWeek of 2023-12-17: DHW 2.5°C-weeks (below the bleaching alert threshold); SST 29.84°CWeek of 2023-12-24: DHW 2.7°C-weeks (below the bleaching alert threshold); SST 30.15°CWeek of 2023-12-31: DHW 4.1°C-weeks (Alert Level 1: significant bleaching likely); SST 30.91°CWeek of 2024-01-07: DHW 5.4°C-weeks (Alert Level 1: significant bleaching likely); SST 30.66°CWeek of 2024-01-14: DHW 5.7°C-weeks (Alert Level 1: significant bleaching likely); SST 30.12°CWeek of 2024-01-21: DHW 5.7°C-weeks (Alert Level 1: significant bleaching likely); SST 29.70°CWeek of 2024-01-28: DHW 5.7°C-weeks (Alert Level 1: significant bleaching likely); SST 29.62°CWeek of 2024-02-04: DHW 5.7°C-weeks (Alert Level 1: significant bleaching likely); SST 29.61°CWeek of 2024-02-11: DHW 5.7°C-weeks (Alert Level 1: significant bleaching likely); SST 29.63°CWeek of 2024-02-18: DHW 5.7°C-weeks (Alert Level 1: significant bleaching likely); SST 29.93°CWeek of 2024-02-25: DHW 4.8°C-weeks (Alert Level 1: significant bleaching likely); SST 30.12°CWeek of 2024-03-03: DHW 5.0°C-weeks (Alert Level 1: significant bleaching likely); SST 30.34°CWeek of 2024-03-10: DHW 5.0°C-weeks (Alert Level 1: significant bleaching likely); SST 29.89°CWeek of 2024-03-17: DHW 5.0°C-weeks (Alert Level 1: significant bleaching likely); SST 29.65°CWeek of 2024-03-24: DHW 4.7°C-weeks (Alert Level 1: significant bleaching likely); SST 30.21°CWeek of 2024-03-31: DHW 4.0°C-weeks (below the bleaching alert threshold); SST 30.24°CWeek of 2024-04-07: DHW 4.2°C-weeks (Alert Level 1: significant bleaching likely); SST 30.19°CWeek of 2024-04-14: DHW 3.9°C-weeks (below the bleaching alert threshold); SST 30.11°CWeek of 2024-04-21: DHW 4.9°C-weeks (Alert Level 1: significant bleaching likely); SST 30.26°CWeek of 2024-04-28: DHW 5.1°C-weeks (Alert Level 1: significant bleaching likely); SST 29.96°CWeek of 2024-05-05: DHW 5.1°C-weeks (Alert Level 1: significant bleaching likely); SST 29.65°CWeek of 2024-05-12: DHW 5.1°C-weeks (Alert Level 1: significant bleaching likely); SST 29.58°CWeek of 2024-05-19: DHW 4.9°C-weeks (Alert Level 1: significant bleaching likely); SST 29.27°CWeek of 2024-05-26: DHW 4.2°C-weeks (Alert Level 1: significant bleaching likely); SST 29.43°CWeek of 2024-06-02: DHW 3.2°C-weeks (below the bleaching alert threshold); SST 29.19°CWeek of 2024-06-09: DHW 3.2°C-weeks (below the bleaching alert threshold); SST 28.71°CWeek of 2024-06-16: DHW 3.2°C-weeks (below the bleaching alert threshold); SST 28.44°CWeek of 2024-06-23: DHW 2.5°C-weeks (below the bleaching alert threshold); SST 28.34°CWeek of 2024-06-30: DHW 1.5°C-weeks (below the bleaching alert threshold); SST 28.35°CWeek of 2024-07-07: DHW 1.2°C-weeks (below the bleaching alert threshold); SST 28.18°CWeek of 2024-07-14: DHW 1.1°C-weeks (below the bleaching alert threshold); SST 28.00°CWeek of 2024-07-21: DHW 0.2°C-weeks (below the bleaching alert threshold); SST 28.04°CWeek of 2024-10-27: DHW 0.1°C-weeks (below the bleaching alert threshold); SST 29.99°CWeek of 2024-11-03: DHW 0.1°C-weeks (below the bleaching alert threshold); SST 29.87°CWeek of 2024-11-10: DHW 1.1°C-weeks (below the bleaching alert threshold); SST 30.23°CWeek of 2024-11-17: DHW 2.4°C-weeks (below the bleaching alert threshold); SST 30.53°CWeek of 2024-11-24: DHW 4.2°C-weeks (Alert Level 1: significant bleaching likely); SST 30.97°CWeek of 2024-12-01: DHW 5.6°C-weeks (Alert Level 1: significant bleaching likely); SST 30.79°CWeek of 2024-12-08: DHW 6.8°C-weeks (Alert Level 1: significant bleaching likely); SST 30.46°CWeek of 2024-12-15: DHW 7.3°C-weeks (Alert Level 1: significant bleaching likely); SST 30.06°CWeek of 2024-12-22: DHW 7.3°C-weeks (Alert Level 1: significant bleaching likely); SST 29.93°CWeek of 2024-12-29: DHW 7.4°C-weeks (Alert Level 1: significant bleaching likely); SST 30.21°CWeek of 2025-01-05: DHW 8.0°C-weeks (Alert Level 2+: severe bleaching and significant mortality likely); SST 30.35°CWeek of 2025-01-12: DHW 8.5°C-weeks (Alert Level 2+: severe bleaching and significant mortality likely); SST 30.17°CWeek of 2025-01-19: DHW 9.3°C-weeks (Alert Level 2+: severe bleaching and significant mortality likely); SST 30.44°CWeek of 2025-01-26: DHW 9.6°C-weeks (Alert Level 2+: severe bleaching and significant mortality likely); SST 30.19°CWeek of 2025-02-02: DHW 9.5°C-weeks (Alert Level 2+: severe bleaching and significant mortality likely); SST 29.66°CWeek of 2025-02-09: DHW 8.5°C-weeks (Alert Level 2+: severe bleaching and significant mortality likely); SST 29.59°CWeek of 2025-02-16: DHW 7.2°C-weeks (Alert Level 1: significant bleaching likely); SST 29.68°CWeek of 2025-02-23: DHW 5.4°C-weeks (Alert Level 1: significant bleaching likely); SST 29.46°CWeek of 2025-03-02: DHW 4.0°C-weeks (Alert Level 1: significant bleaching likely); SST 29.95°CWeek of 2025-03-09: DHW 2.8°C-weeks (below the bleaching alert threshold); SST 30.16°CWeek of 2025-03-16: DHW 2.6°C-weeks (below the bleaching alert threshold); SST 29.83°CWeek of 2025-03-23: DHW 2.6°C-weeks (below the bleaching alert threshold); SST 29.80°CWeek of 2025-03-30: DHW 2.6°C-weeks (below the bleaching alert threshold); SST 29.89°CWeek of 2025-04-06: DHW 1.9°C-weeks (below the bleaching alert threshold); SST 29.83°CWeek of 2025-04-13: DHW 1.6°C-weeks (below the bleaching alert threshold); SST 29.97°CWeek of 2025-04-20: DHW 0.6°C-weeks (below the bleaching alert threshold); SST 29.80°CWeek of 2025-04-27: DHW 0.3°C-weeks (below the bleaching alert threshold); SST 29.85°CWeek of 2025-05-04: DHW 0.3°C-weeks (below the bleaching alert threshold); SST 29.71°CWeek of 2025-05-11: DHW 0.3°C-weeks (below the bleaching alert threshold); SST 29.67°CWeek of 2025-05-18: DHW 0.3°C-weeks (below the bleaching alert threshold); SST 29.68°CWeek of 2025-05-25: DHW 0.3°C-weeks (below the bleaching alert threshold); SST 29.76°CWeek of 2025-06-01: DHW 0.3°C-weeks (below the bleaching alert threshold); SST 29.43°CWeek of 2025-06-08: DHW 0.1°C-weeks (below the bleaching alert threshold); SST 29.25°CWeek of 2025-06-15: DHW 0.1°C-weeks (below the bleaching alert threshold); SST 29.09°CWeek of 2025-11-02: DHW 0.3°C-weeks (below the bleaching alert threshold); SST 30.25°CWeek of 2025-11-09: DHW 0.4°C-weeks (below the bleaching alert threshold); SST 30.18°CWeek of 2025-11-16: DHW 0.6°C-weeks (below the bleaching alert threshold); SST 29.88°CWeek of 2025-11-23: DHW 1.0°C-weeks (below the bleaching alert threshold); SST 30.07°CWeek of 2025-11-30: DHW 1.6°C-weeks (below the bleaching alert threshold); SST 30.31°CWeek of 2025-12-07: DHW 1.6°C-weeks (below the bleaching alert threshold); SST 30.03°CWeek of 2025-12-14: DHW 1.6°C-weeks (below the bleaching alert threshold); SST 30.09°CWeek of 2025-12-21: DHW 1.6°C-weeks (below the bleaching alert threshold); SST 29.93°CWeek of 2025-12-28: DHW 1.6°C-weeks (below the bleaching alert threshold); SST 29.86°CWeek of 2026-01-04: DHW 1.6°C-weeks (below the bleaching alert threshold); SST 29.74°CWeek of 2026-01-11: DHW 1.6°C-weeks (below the bleaching alert threshold); SST 29.53°CWeek of 2026-01-18: DHW 1.6°C-weeks (below the bleaching alert threshold); SST 29.32°CWeek of 2026-01-25: DHW 1.6°C-weeks (below the bleaching alert threshold); SST 29.59°CWeek of 2026-02-01: DHW 1.3°C-weeks (below the bleaching alert threshold); SST 29.59°CWeek of 2026-02-08: DHW 1.0°C-weeks (below the bleaching alert threshold); SST 29.41°CWeek of 2026-02-15: DHW 1.0°C-weeks (below the bleaching alert threshold); SST 29.62°CWeek of 2026-02-22: DHW 0.5°C-weeks (below the bleaching alert threshold); SST 29.50°C26272829303132Bleaching threshold 30.1°C2023202420252026SST (°C)DHW (°C-weeks)
sea surface temperature (SST) (left axis)DHW under 2DHW 2–3DHW 3–5DHW 5–8DHW 8–10DHW over 10 (🔥 above 12)
Daily SST (line) and weekly maximum Degree Heating Weeks (bars), Jan 2023–Sep 2026, NOAA Coral Reef Watch 5-km Maluku virtual station. Dashed line: bleaching threshold (maximum monthly mean 29.1°C + 1°C). DHW ≥ 4: bleaching likely; ≥ 8: severe bleaching and mortality likely. A bar is drawn only where DHW exceeds zero, so a stretch with no bar is accumulated heat stress of zero, not missing data — the SST line runs the full period.

Long-term record: 9 years since 1985 reached 8 or more °C-weeks at NOAA’s Maluku station. Download the annual DHW data (CSV).

7 sites in this region — click a marker to open that site.

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Regional setting

In their Indonesia chapter, Spalding et al. (2001) use the Banda Sea mainly as a boundary. A chain of small archipelagos running from Timor east to the Aru Islands traces its southern margin, within a deep-water sub-region (the Moluccas and Irian Jaya) where islands a few tens of kilometers apart can be divided by more than 1,000 m of mostly clear, oceanic water. They add that the western Banda Sea holds many smaller atolls. Their protected-area list includes two sites named for Banda: the Taman Laut Banda Recreation Park (25 km², designated 1977) and the Gunung Api Banda Recreation Park (7.35 km², 1992). For Indonesia as a whole, they estimate about 51,020 km² of coral reef, 18% of the world total, and record 443 coral species, with 581-602 estimated for the wider biogeographic region. Souter et al. (2021) place the Banda Sea ecoregion in an East Asian Seas subregion of 20,568 km² that also covers Halmahera, Papua, Northeast Sulawesi, the Gulf of Papua, and the Arafura Sea.

Souter et al. (2021) estimate that average hard coral cover across the East Asian Seas was 36.8% in 2019, slightly lower than a decade earlier, a decline they tie to the 2010 and 2016 mass bleaching events; within the Banda Sea's subregion, cover swung widely over the record while algal cover held roughly steady. They name overfishing, expanding coastal aquaculture, and siltation and nutrient enrichment from land-use change as the leading regional pressures, and add marine litter, noting that the region may produce as much as half of the world's marine plastic waste. Wilkinson (2006) had earlier reported that Southeast Asian reefs were still declining in 2004, with overfishing and destructive fishing the dominant direct threats, although Indonesia showed some signs of recovery.

Overview

The seven Banda pins come from 25-28 April 2018: Batu Kapal, an isolated pinnacle in the channel northeast of Banda Neira; Lava Flow, on Gunung Api's 1988 flow; Lighthouse; Airport (Banda Ara); Tanjung Pisang (Banana Island); and Shark Point and Goat Hall on Pulau Ai. Water ran 29.4-30.0°C and was mostly clear. Among the six stations whose recorded depth is a scuba dive, maximum depths ran from 13.7 m at Lava Flow and Lighthouse to 30.5 m at Airport, with Shark Point close behind at 30.2 m; at Tanjung Pisang the recorded 2.4 m is a snorkel over the flat, and the dive there reached 31.4 m. The typical profile is a steep wall or drop-off rising to a shallow terrace or crest. The walls are held largely by filter feeders, with barrel sponges, sea fans, black coral, and Dendronephthya; at Batu Kapal the deep face is sheeted in orange Dendronephthya. The tops carry near-continuous Acropora carpets (Tanjung Pisang, Shark Point, Goat Hall, Lava Flow) or wall-to-wall Sarcophyton and Lobophytum leather-coral terraces (Goat Hall, Batu Kapal).

Sites differ sharply. At Lava Flow the old lava channel now carries essentially complete plate-coral cover beside unbroken staghorn thickets and 20-plus hard coral genera, while angular young basalt in the shallows is only sparsely colonized. Lighthouse pairs a rich coral terrace with a slope of bare volcanic boulders, and Airport includes a long monospecific thicket of Turbinaria- and Pachyseris-type plates. Hard coral cover (Claude CV) across seven sites ranged from 16.4% at Batu Kapal to 54.6% at Lava Flow.

Condition was mixed across the group. Localized bleaching was photographed at Tanjung Pisang (about five large plating colonies stark white with tissue still present), Lighthouse (two bone-white corymbose Acropora), and Lava Flow, where 18 frames show white colonies among pigmented neighbors and 11 show recent staghorn mortality; at Airport, one Stylophora was half bleached and a 2 m Acropora table carried a clean-edged bare patch. Shark Point, Goat Hall, and Batu Kapal showed no bleaching, and no crown-of-thorns was seen on any dive. Hawksbill turtles were photographed at Shark Point and Goat Hall, and Batu Kapal produced a banded sea krait, two large morays, and a clown triggerfish.

Highlights

Notable observations

Coral cover over time (pooled)

One point per year: the mean of every hard coral cover value available for this region that year — Anderson’s own dives and every independent survey station within 5 km of them. The vertical bar is the full range behind that mean. Different programs use different methods at different stations, so this is a regional summary, not a single comparable series. Six values above 70% were excluded as best-patch figures rather than site means. Years resting on fewer than three values are drawn as smaller points (2012, 2020, 2022, 2023). Non-CRD points are from Reef Check Foundation. Marker shape: his own dives, other organizations’ surveys, a mix of both, that year.
0%17%34%51%68%2012201820252012: mean 52% of 2 values (range 44–61%)2014: mean 44% of 3 values (range 40–49%)2015: mean 39% of 9 values (range 23–64%)2016: mean 46% of 13 values (range 24–64%)2017: mean 42% of 11 values (range 19–63%)2018: mean 41% of 25 values (range 16–68%)2019: mean 44% of 33 values (range 11–69%)2020: mean 42% of 2 values (range 29–55%)2022: mean 54% of 2 values (range 52–56%)2023: mean 51% of 2 values (range 44–58%)2024: mean 47% of 4 values (range 40–50%)2025: mean 54% of 6 values (range 44–66%)

Sites in this region

Nearby external survey stations

119 independent survey records within 5 km of a site in this region (deduplicated across sites).

Show all 119 records

All images from Coral Reef Diagnostics. Data are from Coral Reef Diagnostics and Reef Check Foundation.

© Coral Reef Diagnostics.

References