Macrobenthos play a crucial role in monitoring marine ecosystems, as their species composition and community structure are significantly affected by pollution and human activities. Bottom trawling was carried out in October 2022 and March 2023 to collect samples of macrobenthos. A total of twelve macrobenthic samples were collected, and the community composition, species diversity index (H′, J′, D), and ecological status index (AMBI, M-AMBI) were analyzed to determine the seasonal changes, community structure, and ecological status. A total of 94 macrobenthic species were identified, reflecting the biodiversity of the area. This diversity was attributed to the unique topography creating local eddies and upwellings and to effective conservation measures such as fishing restrictions, pollution control, and artificial reef construction. The dominant species included Turritella bacillum and Murex trapa in both seasons, with Oratosquilla oratoria and Bufonaria rana also dominating in autumn. The biodiversity indices were slightly greater in autumn, indicating better community stability. The H′ index revealed moderate disturbance in spring and light disturbance in autumn, whereas the AMBI index suggested no significant disturbance. The M-AMBI index indicated that most stations had good or high ecological statuses. This study revealed good ecological quality in the Nanji Islands, largely due to effective conservation measures and unique environmental conditions.

Herbarium databases can play a crucial role in the study of botany, ecology, and biogeography. With 22,717 specimens, the Nadeaud botanical database of the herbarium of French Polynesia represents a significant resource for the study and preservation of the unique and diverse flora of French Polynesia. This study aims to describe the taxonomic and geographic distributions as well as the ecology of native and endemic vascular plants included in the database. We focused our analysis on native angiosperms representing more than 14,000 specimens, 416 endemic taxa, and 190 non-endemic native taxa. First, the distribution of native angiosperms and the rate of endemism for French Polynesia, for each archipelago and for 60 islands were characterized. The environmental variables associated with each specimen were extracted, which enabled us to document the ecology of the various taxa present in the different archipelagos and islands. We found high rates of endemism in the high-elevation islands, such as the Marquesas and the Society archipelagos, compared to low-lying atolls of the Tuamotu. Environmental correlates enabled us to group them according to their archipelago and/or island endemism, revealing the relevance of the variables chosen for the biogeographical study. The limited geographical distribution of some endemic taxa underlines their vulnerability in relation to certain threatened ecosystems within islands. The taxonomic and geographical distribution of native angiosperms highlights the disparate distribution of taxa among the French Polynesia. This study is an important step toward a better planning of projects related to the preservation of the flora of French Polynesia.

Length-weight relationships (LWR) are valuable for fisheries stock assessments yet are often sparsely available for coral reef fishes. This study describes the LWR for 15 species of coral reef fish spanning seven families from the Northern Line Islands, a geographically remote and historically understudied area of the central Pacific. Specimens were collected across multiple field campaigns from 2006 to 2011, and the LWR were calculated using the linear regression of the log-transformed total length (TL, 0.1 cm precision) and weight (W, 0.01 g precision) data. Many of these species come from popular food fish families and contribute to large proportions of total reef fish biomass. We found that all but one of the Bayesian point estimates fell outside of the 95% confidence interval for our empirically derived LWR, which underscores the importance of studying under-sampled geographies.

Since the introduction of the Golden Pheasant (Chrysolophus pictus) to Haleakalā volcano, Maui, three decades ago, subsequent reports have hinted at an expansion of this nascent population. We draw from a variety of data sources to learn about this pheasant's present status on Maui. First, forest bird surveys conducted every five years revealed that the frequency of Golden Pheasant detections has greatly increased, and the bird has both maintained its former distribution and expanded eastward into Haleakalā National Park (NP). Second, reports to eBird from The Nature Conservancy's Waikamoi Preserve, where Golden Pheasants first appeared on Maui, demonstrate that the frequency of observations has increased and is strongly seasonal, predominantly in the spring. Third, autonomous recording units monitoring endangered forest birds recorded pheasants too, adding new locations. Finally, trail cameras set to monitor mammals picked up pheasants as well, showing males of two color morphs: original “wild-type” and “dark-throated.” Trail cameras also documented a small juvenile at Waikamoi Preserve and both females and males in Haleakalā NP. By “connecting the dots” of mapped occurrences, we traced the pheasant's progression through a narrow band of subalpine cloud forest with open understory, extending from Waikamoi Preserve eastward to upper Kīpahulu Valley, a distance of 14 km. In summary, this body of evidence supports the claim that the Golden Pheasant has established a self-sustaining population on Maui, and we propose that the species' success there may be attributed to the minimal influence of predators and the absence of competing gallinaceous birds in its preferred habitat.

On the Hawaiian Island of O‘ahu, nearly 1,500 on-site sewage disposal systems (OSDS) exist within the Kāne‘ohe Bay drainage basin, releasing an estimated 3,800 cubic meters (one million gallons) of untreated wastewater into the groundwater each day, threatening stream and coastal water quality. The study area—Kahalu‘u, Hawai‘i—is characterized by the highest density (units per area) of OSDS in the Kāne‘ohe Bay drainage basin. This study evaluates hydrologic flow paths from wastewater point sources to groundwater and surface waters by utilizing a combination of unmanned aerial vehicle thermal infrared (UAV-TIR) imaging, stream gauging and seepage runs, and numerical groundwater models (MODFLOW and MT3DMS). Eight coastal groundwater seep locations were identified with UAV-TIR, with all seeps occurring through coastal valley fill sediments. Geochemical analysis of seeps revealed significantly elevated concentrations of all major nutrients compared to surrounding ocean waters. Groundwater nitrogen transport was modeled with MT3DMS and compared to measured concentrations. Most OSDS are located within the valley fill, and MODFLOW results suggest that the valley fill is more hydraulically conductive than the surrounding dike-intruded basalt, thus controlling groundwater and contaminant dispersion to streams and the ocean. Modeling also reveals that groundwater flow from leeward of the Ko‘olau ridgeline and from adjacent watersheds to the southeast may be significant hydrologic inputs to the study area.

Introduced ungulates have a profound impact on Hawaiian ecosystems yet are also considered a valuable resource for recreational and subsistence hunting. These conflicting values have led to challenging issues for resource managers. Distribution assessments allow resource managers to simultaneously prioritize areas for targeted removal for conservation benefit while also maintaining or even promoting hunting opportunities in other areas. This study identified distribution trends for three introduced ungulate species, wild pigs (Sus scrofa), black-tailed deer (Odocoileus hemionus columbianus), and feral goats (Capra hircus) on the island of Kaua‘i in the Hawaiian Islands. Using species distribution modeling techniques, we aimed to identify patterns in ungulate distributions across ecosystems and time, and potential species interactions. Data were collected using motion activated cameras deployed across the entire island of Kaua‘i from July 2020 to July 2021. Wild pigs were the most frequently detected species, observed at 53 out of 59 locations, followed by black-tailed deer at 30 locations, and feral goats at 9 locations. Distribution models indicate some degree of competition between deer and pigs and show considerable overlap between black-tailed deer distribution and much of the last remaining critical habitat for threatened and endangered native species. Our results suggest that pigs prefer mid-elevation areas with moderate rainfall while goats preferred arid areas regardless of slope and elevation. Differences in the distribution and abundance of these species highlight the divergent impacts invasive ungulates have on native ecosystems throughout the Hawaiian Islands and may help identify high priority areas for their management.

Laysan Albatross (Phoebastria immutabilis) fledged the first chick on the island of O‘ahu in 1947, but did not begin regularly breeding until 1992, followed by Black-footed Albatross (P. nigripes) who began breeding in 2022. Laysan Albatross have attempted to breed at nine locations on O‘ahu since 1979 and have established colonies at four sites: Ka‘ena Point, Kuaokala-, Kahuku Point, and James Campbell National Wildlife Refuge. We monitored Laysan Albatross colonies on O‘ahu weekly from 2004 to 2023; all individuals were censused, banded, and identified to gender. There was a population of 875 adults on O‘ahu in 2023, 490 of which were active breeders. The annual growth rate up to 2015 was 26%, but the growth rate slowed to 20% after human vandalism in 2015 that resulted in the destruction of 17 nests and at least 17 adults. The advent of predator exclusion fencing at Ka‘ena Point (2011) and Kuaokala- (2021) resulted in increased reproductive success (from 0.37 to 0.43) driven by a 25% increase in chick fledging success (from 0.60 before fencing to 0.80 after) which resulted in an estimated additional 69 chicks fledging compared to if the fence had not been constructed. Black-footed Albatross visits increased to O‘ahu from 3 in 2017 to 317 in 2023, coinciding with the disappearance of East Island in Papaha-naumokua-kea Marine National Monument which displaced 2,000 breeding pairs. These new colonies are at higher elevations and will continue to serve as refugia against sea level rise and as such, are conservation priorities.

Birds often prey on agricultural pests, potentially making them effective pest management agents; thus, changes in bird populations may have impacts on plant health. Using an exclosure treatment, we test whether birds reduce herbivore damage and increase crop yield on the island of Luta in the Mariana Island chain. We focused on Luta because the nearby island of Guåhan has experienced widespread bird loss due to an invasive snake, and thus, this experiment simulating bird loss could provide an indication of potential cascading impacts to agriculture on Guåhan. We planted two crops—eggplant and long bean—within bird exclosure and control treatments at three working farms, and measured herbivore damage, crop yield, and spider web abundance in the presence and absence of birds. The influence of birds varied among crops and farms. Herbivore damage did not differ between treatments in long bean, but damage was greater for eggplant in the absence of birds at one farm ("Farm 3"). Yield of eggplant did not differ between treatments, but yield and weight of long bean was lower in the absence of birds at Farm 1. Spider webs were 270% greater in the absence of birds at Farm 1, whereas spider webs were more abundant in the presence of birds at the other two farms. These results suggest that birds may control pest populations, but the effects vary depending on the crop and environmental context.

Between 1958 and 2018, multiple roadside surveys were conducted on the upper altitudinal limits of the alpine Maunaloa (now preferred Hawaiian language spelling of Mauna Loa) vascular flora from near tree line (2,525 m) to the NOAA Mauna Loa Observatory (MLO) at 3,397 m. Five native plant species were encountered in 1958 on numerous sparsely vegetated historic and prehistoric basaltic lava flows. A resurvey of the roadside 50 years later (2008) yielded 22 species including nine new native species and eight aliens. The aliens were limited to a few individuals at sites disturbed by human activity. Here, floristic change along the transect was reassessed after 60 years (2018), recording a total of 30 species with 15 natives and 15 aliens. Floristic diversity and shifts in altitudinal limits are evaluated in relation to well documented and dramatic local climate change over recent decades, along with the competing influences of substrate-control and increasing human disturbance. The results indicate that lava substrate age and textural variation, along with human mediated propagule pressure, and associated disturbance exert greater impact than rapid climate change in explaining current patterns of plant distribution and diversity in this hyper-arid, alpine environment. This long-term monitoring effort of alpine lava flows has also informed and reinforced a more general moisture/ substrate-control model for early primary succession extending to lower subalpine mountain elevations involving the two dominant lava flow textural classes: ‘a‘ā and pāhoehoe.