Crowdsourcing conservation: The role of citizen science in securing a future for seagrass

Seagrass meadows are complex social-ecological systems. Understanding seagrass meadows demands a fresh approach integrating “the human dimension”. Citizen science is widely acknowledged for providing significant contributions to science, education, society and policy. Although the take up of citizen science in the marine environment has been slow, the need for such methods to fill vast information gaps is arguably great. Seagrass meadows are easy to access and provide an example of where citizen science is expanding. Technological developments have been pivotal to this, providing new opportunities for citizens to engage with seagrass. The increasing use of online tools has created opportunities to collect and submit as well as help process and analyse data. Citizen science has helped researchers integrate scientific and local knowledge and engage communities to implement conservation measures. Here we use a selection of examples to demonstrate how citizen science can secure a future for seagrass

Seagrass ecosystem contributions to people's quality of life in the Pacific Island Countries and Territories

Seagrass ecosystems provide critical contributions (goods and perceived benefits or detriments) for the livelihoods and wellbeing of Pacific Islander peoples. Through in-depth examination of the contributions provided by seagrass ecosystems across the Pacific Island Countries and Territories (PICTs), we find a greater quantity in the Near Oceania (New Guinea, the Bismarck Archipelago and the Solomon Islands) and western Micronesian (Palau and Northern Marianas) regions; indicating a stronger coupling between human society and seagrass ecosystems. We also find many non-material contributions historically have been overlooked and under-appreciated by decision-makers. Closer cultural connections likely motivate guardianship of seagrass ecosystems by Pacific communities to mitigate local anthropogenic pressures. Regional comparisons also shed light on general and specific aspects of the importance of seagrass ecosystems to Pacific Islanders, which are critical for forming evidence-based policy and management to ensure the long-term resilience of seagrass ecosystems and the contributions they provide

Seagrass ecosystems of the Pacific Island countries and territories: a global bright spot

Seagrass ecosystems exist throughout Pacific Island Countries and Territories (PICTs). Despite this area covering nearly 8% of the global ocean, information on seagrass distribution, biogeography, and status remains largely absent from the scientific literature. We confirm 16 seagrass species occur across 17 of the 22 PICTs with the highest number in Melanesia, followed by Micronesia and Polynesia respectively. The greatest diversity of seagrass occurs in Papua New Guinea (13 species), and attenuates eastward across the Pacific to two species in French Polynesia. We conservatively estimate seagrass extent to be 1446.2 km2, with the greatest extent (84%) in Melanesia. We find seagrass condition in 65% of PICTs increasing or displaying no discernible trend since records began. Marine conservation across the region overwhelmingly focuses on coral reefs, with seagrass ecosystems marginalised in conservation legislation and policy. Traditional knowledge is playing a greater role in managing local seagrass resources and these approaches are having greater success than contemporary conservation approaches. In a world where the future of seagrass ecosystems is looking progressively dire, the Pacific Islands appears as a global bright spot, where pressures remain relatively low and seagrass more resilient

Lack of Phylogeographic Structure in the Freshwater Cyanobacterium Microcystis aeruginosa Suggests Global Dispersal

Background : Free-living microorganisms have long been assumed to have ubiquitous distributions with little biogeographic signature because they typically exhibit high dispersal potential and large population sizes. However, molecular data provide contrasting results and it is far from clear to what extent dispersal limitation determines geographic structuring of microbial populations. We aimed to determine biogeographical patterns of the bloom-forming freshwater cyanobacterium Microcystis aeruginosa. Being widely distributed on a global scale but patchily on a regional scale, this prokaryote is an ideal model organism to study microbial dispersal and biogeography. Methodology/Principal Findings : The phylogeography of M. aeruginosa was studied based on a dataset of 311 rDNA internal transcribed spacer (ITS) sequences sampled from six continents. Richness of ITS sequences was high (239 ITS types were detected). Genetic divergence among ITS types averaged 4% (maximum pairwise divergence was 13%). Preliminary analyses revealed nearly completely unresolved phylogenetic relationships and a lack of genetic structure among all sequences due to extensive homoplasy at multiple hypervariable sites. After correcting for this, still no clear phylogeographic structure was detected, and no pattern of isolation by distance was found on a global scale. Concomitantly, genetic differentiation among continents was marginal, whereas variation within continents was high and was mostly shared with all other continents. Similarly, no genetic structure across climate zones was detected. Conclusions/Significance : The high overall diversity and wide global distribution of common ITS types in combination with the lack of phylogeographic structure suggest that intercontinental dispersal of M. aeruginosa ITS types is not rare, and that this species might have a truly cosmopolitan distribution

Over a decade monitoring Fiji's seagrass condition demonstrates resilience to anthropogenic pressures and extreme climate events

Seagrass are an important marine ecosystem of the Fiji Islands. We confirm six seagrass species from the archipelago and defined five broad categories of seagrass habitat. We report, with high confidence, seagrass meadows covering 59.19 km2 of Fiji's shallow water habitats from literature and this study. Long-term monitoring of seagrass abundance, species composition, and seed banks at eight sentinel sites, found no long-term trends. Examination of key attributes that affect seagrass resilience identified meadows as predominately enduring and dominated by opportunistic species which had moderate physiological resistance, and high recovery capacity. We examined threats to Fiji's seagrass meadows from extreme climatic events and anthropogenic activities using a suite of indicators, identifying water quality as a major pressure. Based on these findings, we assessed existing protections in Fiji afforded to seagrass and their services. This understanding will help to better manage for seagrass resilience and focus future seagrass research in Fiji

Disturbance influences the invasion of a seagrass into an existing meadow

Future impacts from climate change and human activities may increase the likelihood of invasions of native marine species into existing habitats as a result of range shifts. To provide an understanding of the invasion of a native seagrass species (Syringodium isoetifolium) into a tropical multi-species meadow, detailed field assessments were conducted over a six year period. After establishing in a discrete patch, the extent and standing crop of S. isoetifolium increased 800 and 7000 fold, respectively, between 1988 and 2003 (~300–260,000 m2 and <1 kg DW to 7596 ± 555 kg DW). The expansion of S. isoetifolium was confined to subtidal areas and appears primarily from clonal growth. The observed expansion of this species into a new locality was found to be clearly influenced by cumulative impacts and chronic small-scale physical disturbances. This study has immediate relevance to managing impacts which influence the spread of invasive species

Seagrass habitats of Singapore: environmental drivers and key processes

Seagrasses are an important component of the marine ecosystems of Singapore. Using various assessment activities, we confirm 10 seagrass species within the waters of Singapore, with an additional two species under review for synonymy. Using long-term monitoring we examined the key attributes that affect the resilience of Singapore's seagrasses. We defined five broad categories of seagrass habitat in Singapore as estuary, coast, rocky fringing reef, sandy fringing reef, and patch reef. We identify the key features of the habitats and provide some insight into the drivers of change. In their natural state, seagrasses appear to follow a unimodal pattern of growth annually, which peaks in the late intermonsoon period prior to the onset of the southwest monsoon. Light availability appears to be the critical factor for seagrass growth in Singapore, and environmental factors, which modify the interactive effect of light availability and temperature are possibly the main drivers of change. Finally, we synthesised our understanding of seagrass ecosystems by classifying the attributes of the species present, meadow structure, and their possible drivers into a framework to assist ongoing monitoring and management decision-making. We also discuss the implications of seasonal growth in the Singapore context and identify research gaps that need to be urgently addressed. This understanding will help to better focus seagrass management and research in Singapore

Seagrass habitats of Singapore: environmental drivers and key\ud processes

Seagrasses are an important component of the marine ecosystems of Singapore. Using various assessment activities, we confirm 10 seagrass species within the waters of Singapore, with an additional two species under review for synonymy. Using long-term monitoring we examined the key attributes that affect the resilience of Singapore's seagrasses. We defined five broad categories of seagrass habitat in Singapore as estuary, coast, rocky fringing reef, sandy fringing reef, and patch reef. We identify the key features of the habitats and provide some insight into the drivers of change. In their natural state, seagrasses appear to follow a unimodal pattern of growth annually, which peaks in the late intermonsoon period prior to the onset of the southwest monsoon. Light availability appears to be the critical factor for seagrass growth in Singapore, and environmental factors, which modify the interactive effect of light availability and temperature are possibly the main drivers of change. Finally, we synthesised our understanding of seagrass ecosystems by classifying the attributes of the species present, meadow structure, and their possible drivers into a framework to assist ongoing monitoring and management decision-making. We also discuss the implications of seasonal growth in the Singapore context and identify research gaps that need to be urgently addressed. This understanding will help to better focus seagrass management and research in Singapore