Hawaiʻi Coral Disease database (HICORDIS):species-specific coral health data from across the Hawaiian archipelago

AbstractThe Hawaiʻi Coral Disease database (HICORDIS) houses data on colony-level coral health condition observed across the Hawaiian archipelago, providing information to conduct future analyses on coral reef health in an era of changing environmental conditions. Colonies were identified to the lowest taxonomic classification possible (species or genera), measured and assessed for visual signs of health condition. Data were recorded for 286,071 coral colonies surveyed on 1819 transects at 660 sites between 2005 and 2015. The database contains observations for 60 species from 22 genera with 21 different health conditions. The goals of the HICORDIS database are to: i) provide open access, quality controlled and validated coral health data assembled from disparate surveys conducted across Hawaiʻi; ii) facilitate appropriate crediting of data; and iii) encourage future analyses of coral reef health. In this article, we describe and provide data from the HICORDIS database. The data presented in this paper were used in the research article “Satellite SST-based Coral Disease Outbreak Predictions for the Hawaiian Archipelago” (Caldwell et al., 2016) [1]

Histopathology of Growth Anomaly Affecting the Coral, Montipora capitata: Implications on Biological Functions and Population Viability

Growth anomalies (GAs) affect the coral, Montipora capitata, at Wai'ōpae, southeast Hawai'i Island. Our histopathological analysis of this disease revealed that the GA tissue undergoes changes which compromise anatomical machinery for biological functions such as defense, feeding, digestion, and reproduction. GA tissue exhibited significant reductions in density of ova (66.1–93.7%), symbiotic dinoflagellates (38.8–67.5%), mesenterial filaments (11.2–29.0%), and nematocytes (28.8–46.0%). Hyperplasia of the basal body wall but no abnormal levels of necrosis and algal or fungal invasion was found in GA tissue. Skeletal density along the basal body wall was significantly reduced in GAs compared to healthy or unaffected sections. The reductions in density of the above histological features in GA tissue were collated with disease severity data to quantify the impact of this disease at the colony and population level. Resulting calculations showed this disease reduces the fecundity of M. capitata colonies at Wai'ōpae by 0.7–49.6%, depending on GA severity, and the overall population fecundity by 2.41±0.29%. In sum, GA in this M. capitata population reduces the coral's critical biological functions and increases susceptibility to erosion, clearly defining itself as a disease and an ecological threat

Variation in Symbiodinium ITS2 Sequence Assemblages among Coral Colonies

Endosymbiotic dinoflagellates in the genus Symbiodinium are fundamentally important to the biology of scleractinian corals, as well as to a variety of other marine organisms. The genus Symbiodinium is genetically and functionally diverse and the taxonomic nature of the union between Symbiodinium and corals is implicated as a key trait determining the environmental tolerance of the symbiosis. Surprisingly, the question of how Symbiodinium diversity partitions within a species across spatial scales of meters to kilometers has received little attention, but is important to understanding the intrinsic biological scope of a given coral population and adaptations to the local environment. Here we address this gap by describing the Symbiodinium ITS2 sequence assemblages recovered from colonies of the reef building coral Montipora capitata sampled across Kāne'ohe Bay, Hawai'i. A total of 52 corals were sampled in a nested design of Coral Colony(Site(Region)) reflecting spatial scales of meters to kilometers. A diversity of Symbiodinium ITS2 sequences was recovered with the majority of variance partitioning at the level of the Coral Colony. To confirm this result, the Symbiodinium ITS2 sequence diversity in six M. capitata colonies were analyzed in much greater depth with 35 to 55 clones per colony. The ITS2 sequences and quantitative composition recovered from these colonies varied significantly, indicating that each coral hosted a different assemblage of Symbiodinium. The diversity of Symbiodinium ITS2 sequence assemblages retrieved from individual colonies of M. capitata here highlights the problems inherent in interpreting multi-copy and intra-genomically variable molecular markers, and serves as a context for discussing the utility and biological relevance of assigning species names based on Symbiodinium ITS2 genotyping

Kū‘ula: Nurturing a generation of Indigenous leadership for marine conservation in Hawai‘i

“Kū‘ula: Integrated Science” was developed as an official undergraduate–graduate dual-level course at the University of Hawaiʻi at Hilo. It aimed to provide research and service-learning opportunities in natural resource management that integrated Native Hawaiian and Western sciences. So far, it has served four cohorts of students, mostly Native Hawaiian. In this article, we offer summaries of how this course impacted participants while they were students and in their post-graduation careers. The participant voices illustrate the deep and long-lasting impacts of their experiences with Kū‘ula, some by academic content but mostly because of experiential and peer-learning. Such impacts are lasting well beyond their graduation into their careers now. Kūʻula participants resoundingly advocate for University of Hawai‘i campuses to offer place-based pedagogical frameworks that integrate Native Hawaiian knowledge and epistemologies

Exposure to sediment enhances primary acquisition of Symbiodinium by asymbiotic coral larvae

Many symbiotic marine invertebrates acquire free-living Symbiodinium from the environment. Abundance and diversity of free-living Symbiodinium could influence recovery from\ud bleaching, resilience, and the long-term adaptation of host organisms. Although free-living Symbiodinium have been detected in the water column and substrates of coral reefs, their diversity and availability to the hosts are poorly understood. Tank experiments were conducted to test whether\ud asymbiotic coral larvae of Acropora monticulosa acquired free-living Symbiodinium from the water column or sediment to become symbiotic. Treatments included filtered (0.22 μm) seawater (FSW), unfiltered seawater (SW), FSW and sediment, and SW and sediment. Our results showed that greater proportions of larvae in sediment-containing treatments acquired Symbiodinium earlier and had greater in hospite Symbiodinium densities when compared to seawater-only treatments. Additionally, clade A Symbiodinium was only recovered in the larvae from the sediment-containing treatments, whereas clades B and C were recovered from all treatments. Differences in distribution, abundance,\ud replication and motility patterns of Symbiodinium, as well as larval behavior, may have contributed to the observed differences between uptake from the sediment and the water column. However, our results suggest that the sediment may represent an important source of free-living Symbiodinium available for uptake during primary acquisition by coral larvae

RESPONSE OF GLUTAMINE SYNTHETASE GENE TRANSCRIPTION AND ENZYME ACTIVITY TO EXTERNAL NITROGEN SOURCES IN THE DIATOM SKELETONEMA COSTATUM

To anderstand the enhanced ability of marine diatoms to assimilate nitrogen (N), we measured changes in the transcript abundance and enzyme activity of glutamine synthetase (GS), one of the key enzymes that link carbon (C) and N metabolism, in the common diatom Skeletonema costatum (Greville) Cleve. Transcript abundance of glnII (the gene that encodes the GSII isoenzyme), measured by quantitative reverse transcriptase-PCR, and total GS activity increased 2 to 3.5 times above background in the cells taking up nitrate (NO3-) but not the cells taking up ammonium (NH 4+). A background level of glnII mRNA was maintained at a steady level up to 15 days of N starvation before decreasing to below detection after 21 days. These results confirm that transcription of glnII is induced to assimilate NH4+ derived from reduction of NO 3-. Because of this role of GSII in diatoms assimilating NH4+ derived from NO3- reduction rather than from the environmental NH4+, quantification of glnII mRNA promises to be a useful indication of new production by phytoplankton

Impacts of GA on <i>M. capitata</i> tissue characteristics at the population level.

<p>Summary of the reductions in densities of ova, symbiotic dinoflagellates, mesenterial filaments, and nematocytes seen in Type A and B growth anomalies (GAs), compared to the healthy tissue from histological analysis. Mean values of Type A and Type B severity are shown for all colonies surveyed in this population (n = 1093). The reductions in these parameters were combined with GA severity data (right column, from Burns et al. 2011) to estimate their impacts at the population level (bottom row).</p

Sagittal histological sections.

<p>Sagittal histological sections of the coral, <i>Montipora capitata</i>. <b>a.</b> Healthy tissue. Note the developing ova (O), mesenterial filaments (MF), and nematocytes (N). <b>b.</b> Unaffected tissue directly adjacent to GA. Note the developing ova (O), mesenterial filaments (MF), and nematocytes (N). No evidence of hyperplasia or cellular irregularity is present. <b>c.</b> Type A growth anomaly (GA). Note the hyperplasia and disorganization of the basal body wall (H), reduced numbers of mesenterial filaments (MF), and absence of ova. <b>d.</b> Type B GA. Note complete absence of ova and mesenterial filaments with marked hyperplasia (H) of the basal body wall. Bars = 250 µm.</p

Type A and Type B GA morphology.

<p>Photographs of Type A and Type B GA tissue <b>a.</b> Type A GA, note reduction in polyps (arrows) and fused protrusive tuberculae. <b>b.</b> Type B GA, note lack of polyps and fused protuberant coenosteum.</p