Gabriel Grimsditch

Gabriel Grimsditch
United Nations Environment Programme · Convention on Migratory Species

MSc

About

64
Publications
35,803
Reads
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1,494
Citations
Additional affiliations
June 2017 - March 2022
United Nations Environment Programme
Position
  • Programme Management Officer for Coastal Ecosystems & Climate Change
March 2014 - June 2017
International Union for Conservation of Nature
Position
  • Senior Project Officer/Chief Technical Officer
July 2009 - March 2014
United Nations Environment Programme
Position
  • Associate Programme Officer for Coastal Ecosystems

Publications

Publications (64)
Technical Report
Full-text available
Founded in 1958, IUCN (the International Union for the Conservation of Nature) brings together states, government agencies and a diverse range of non-governmental organizations in a unique world partnership: over 100 members in all, spread across some 140 countries. As a Union, IUCN seeks to influence, encourage and assist societies throughout the...
Technical Report
Full-text available
This report focuses on the management of natural coastal carbon sinks. The produc�on of the report has been s�mulated by an apparent lack of recogni�on • and focus on coastal marine ecosystems to comple- ment ac�vi�es already well advanced on land to ad- dress the best prac�ce management of carbon sinks. The produc�on of this report is �mely as a n...
Technical Report
Full-text available
With accelerating declines of coral reefs globally and the start of the UN Decade on Ecosystem Restoration, the need for better understanding the effectiveness of coral reef restoration efforts, particularly in supporting the maintenance of ecosystem services, is accelerating. This document presents an overview of the best-available knowledge in th...
Technical Report
Full-text available
The third global coral bleaching event, which started in 2014 and extended well into 2017, was the longest coral bleaching event on record. The length of the event means corals in some parts of the world had no time to recover in 2014, 2015 or 2016 during the cool/winter season, prior to experiencing bleaching the following year. This recent global...
Article
Full-text available
Blue Carbon Ecosystems (BCEs) help mitigate and adapt to climate change but their integration into policy, such as Nationally Determined Contributions (NDCs), remains underdeveloped. Most BCE conservation requires community engagement, hence community-scale projects must be nested within the implementation of NDCs without compromising livelihoods o...
Technical Report
Full-text available
Ocean ecosystems play a key role in maintaining the integrity of our biosphere, but vary widely with respect to their biodiversity attributes, their relationship with the atmosphere and climate change processes, and the ecosystem services that they provide to humans. Coral reefs and ecologically associated coastal ecosystems, such as intertidal man...
Chapter
Full-text available
The Western Indian Ocean (WIO) region comprises almost 6% (about 15,180 km2) of the total global area of coral reefs, and the region is a globally important hotspot for coral reef biodiversity. The WIO includes sovereign states along the eastern and southern African mainland (Somalia, Kenya, Tanzania, Mozambique, South Africa), island states (Mauri...
Article
Full-text available
Seagrass meadows deliver multiple ecosystem services that are of particular importance to resource-poor coastal communities, yet they are rapidly declining globally. The Payments for Ecosystem Services (PES) approach has been used to fund the protection of other ‘Blue Carbon’ Ecosystems (BCE), yet seagrass has been incorporated in just one PES proj...
Article
Seagrass meadows deliver multiple ecosystem services that are of particular importance to resource-poor coastal communities, yet they are rapidly declining globally. The Payments for Ecosystem Services (PES) approach has been used to fund the protection of other ‘Blue Carbon’ Ecosystems (BCE), yet seagrass has been incorporated in just one PES proj...
Article
Full-text available
In 2019, the United Nations Environment Assembly requested that the United Nations Environment Programme (UNEP) and the International Coral Reef Initiative (ICRI) define best practices for coral restoration. Guidelines led by the UNEP were prepared by a team of 20 experts in coral reef management, science, and policy to catalog the best-available k...
Article
Reduction in the impact of human-induced factors is capable of enhancing the environmental health. In view of COVID-19 pandemic, lockdowns were imposed in India. Travel, fishing, tourism and religious activities were halted, while domestic and industrial activities were restricted. Comparison of the pre- and post-lockdown data shows that water para...
Technical Report
Full-text available
Policy brief associated with the UNEP and ICRI report" Coral Reef Restoration as a strategy to improve ecosystem services: A guide to coral restoration methods"
Article
Full-text available
Climate change is causing the decline of coral reef ecosystems globally. Recent research highlights the importance of reducing CO 2 emissions in combination with implementing local management actions to support reef health and recovery, particularly actions that protect sites which are more resilient to extreme events. Resilience assessments quanti...
Article
This study compares the occurrence and characteristics of microplastics (MPs) and heavy metal contaminants in the water and sediment of three habitats (corals, seagrass-beds and near-shores) of Rameswaram Island, India. The overall mean concentration of MPs varies from 24 ± 9 to 96 ± 57 items/L in water, and from 55 ± 21 to 259 ± 88 items/kg in sed...
Technical Report
Full-text available
Seagrass meadows are important marine ecosystems, providing a range of services including carbon sequestration, nursery habitats for fish and coastal protection. They are suffering rapid global decline in the face of eutrophication and other pollution, damage caused by fishing activities, tourism and coastal development. Degradation and loss of sea...
Article
Full-text available
Complex histories of chronic and acute sea surface temperature (SST) stresses are expected to trigger taxon- and location-specific responses that will ultimately lead to novel coral communities. The 2016 El Niño-Southern Oscillation provided an opportunity to examine largescale and recent environmental histories on emerging patterns in 226 coral co...
Article
Full-text available
Aim Predictions for the future of coral reefs are largely based on thermal exposure and poorly account for potential geographic variation in biological sensitivity to thermal stress. Without accounting for complex sensitivity responses, simple climate exposure models and associated predictions may lead to poor estimates of future coral survival and...
Technical Report
Full-text available
The Foresight Briefs are published by the United Nations Environment Programme to highlight a hotspot of environmental change, feature an emerging science topic, or discuss a contemporary environmental issue. The public is provided with the opportunity to find out what is happening to their changing environment and the consequences of everyday choi...
Technical Report
Full-text available
This document does not provide step-by-step instructions on running a community-based seagrass conservation project; it does however provide guidance and best-practice advice on how to do so and acts as a ‘signposting’ guide to resources elsewhere. The scope of the document is intended to be global and so details of country-specific legislation, cu...
Article
Underwater survey was conducted to assess the accumulation and impact of marine debris in the reef areas of Gulf of Mannar in southeast India. A combination of roving diver technique and belt transect method was applied for the assessment, which was conducted during the period between February 2018 and March 2019. An estimated total reef area of 11...
Article
Full-text available
Under extreme heat stress, corals expel their symbiotic algae and colour (that is, ‘bleaching’), which often leads to widespread mortality. Predicting the large-scale environmental conditions that reinforce or mitigate coral bleaching remains unresolved and limits strategic conservation actions1,2. Here we assessed coral bleaching at 226 sites and...
Article
Full-text available
ABSTRACT: During the third global coral bleaching event in 2016, the Maldives experienced elevated water temperatures inducing coral bleaching. The bleaching intensity and mortality of coral communities was recorded in different habitats, depths, and wave exposure conditions around North Ari Atoll in the central Maldives to investigate the effect o...
Article
During the third global coral bleaching event in 2016, the Maldives experienced elevated water temperatures, inducing coral bleaching. We recorded the bleaching intensity and mortality of coral communities in different habitats, depths and wave exposure conditions around North Ari Atoll in the central Maldives to investigate the effect of physical...
Article
There is global consensus that marine protected areas offer a plethora of benefits to the biodiversity within and around them. Nevertheless, many organisms threatened by human impacts also find shelter in unexpected or informally protected places. For coral reef organisms, refuges can be tourist resorts implementing local environment-friendly botto...
Article
This study aimed to assess how the size-frequency distributions of coral genera varied between reefs under different fishing pressures in two contrasting Indian Ocean locations (the Maldives and East Africa). Using generalized linear mixed models, we were able to demonstrate that complex interactions occurred between coral genera, coral size class...
Technical Report
Full-text available
This report aimed at understanding resource use and dependence, perception of marine conservation policies, and adaptive capacities of communities of North Ari atoll, Maldives. It provides information on the social resilience of 8 local community islands in North Ari atoll, and identifies differences in gender role, in resource use and perception o...
Technical Report
Full-text available
This report represents the most comprehensive effort to monitor coral bleaching in the Maldives to date, using a combination of citizen science and expert scientist (governmental, academic and non-governmental) data sets. The 2015-2016 El Niño weather phenomena and associated sea surface temperature anomalies in 2016 caused one of the largest recor...
Technical Report
Full-text available
Coastal and marine ecosystems provide a wide variety of benefits to humans in the form of goods and services; collectively these are termed marine ecosystem services. In the Republic of the Maldives, coral reefs and associated habitats provide valuable ecosystem services such as fish and other food, natural hazard protection, climate regulation and...
Chapter
This study explores the patterns of coral recruitment, survivorship and resilience on the coral reefs of the west coast of Pemba Island, Tanzania. The results show that recovery from the 1998 mass coral bleaching event has been patchy, with great variation in coral cover among sites, and a generally high macroalgal cover. Sites with low coral recov...
Chapter
Full-text available
Understanding factors that promote coral reef resilience to climatic and anthropogenic stressors is required in order to develop methods and decision support systems to establish resilient Marine Protected Areas (MPAs) and other marine managed areas. This study presents an analysis of coral reef resilience factors obtained from a rapid assessment o...
Article
Full-text available
On Bonaire, we studied the effects of predator abundance and habitat availability on the abundance of the threespot damselfish Stegastes planifrons, a species that creates algal gardens at the expense of live coral cover. Across 21 sites, predator biomass ranged from 12 to 193 g m-2 (mean = 55.1; SD = 49.1) and benthic cover of S. planifrons' prefe...
Chapter
Full-text available
We present results of the field assessment using a total of fifteen 0.1 ha mangrove permanent sample plots (PSPs) in four selected countries in Central Africa, including: Cameroon, Gabon, Republic of Congo and Democratic of Republic, which together account for 90 % of mangroves in Central Africa. Above-and belowground carbon stocks were computed us...
Technical Report
Full-text available
In recent years, increasing international attention has focused on the potential of coastal and marine vegetative systems as a new opportunity to sequester and store the greenhouse gas carbon dioxide (CO2). Recent research around the world has highlighted the valuable role that coastal and marine ecosystems play in sequestering and storing CO2. Thi...
Technical Report
Full-text available
This report presents the results of a study carried out to assess the carbon pools, ecosystem services and multiple benefits of the mangroves in the Central African countries of Cameroon, Gabon, Republic of Congo (RoC) and Democratic Republic of Congo (DRC). Mangroves are among the most carbon-rich ecosystems in the world, and also provide valuable...
Article
Healthy ecosystems provide vital services for urban centres as well as for adaptation of urban communities to climate change. This paper will describe the value of ecosystem services and ecosystem-based adaptation for urban centres, giving examples of the effectiveness of this approach. It also provides possible policy recommendations for urban pla...
Technical Report
Full-text available
Although Bonaire’s coral reefs remain among the healthiest and most resilient in the Caribbean, this IUCN report based on the IUCN Resilience Assessment of Coral Reefs highlights some of the threats that exist to Bonaire’s coral reefs, and which could have serious implications for resilience to future climate change and other threats. The report id...
Article
Full-text available
Abstract—Coral bleaching (loss of zooxathellae) is an increasing problem for the health and persistence of corals, but the phenomenon can not be fully comprehended without understanding seasonal fluctuations in the field. Seasonal dynamics of coral zooxanthellae (population density and mitotic indices) of eleven scleractinian coral species (Acropor...
Article
Full-text available
This study examines the bleaching responses of scleractinian corals at four sites in Kenya (Kanamai, Vipingo, Mombasa and Nyali) representing two distinct lagoon habitats (relatively shallow and relatively deep). Bleaching incidence was monitored for the whole coral community, while zooxanthellae densities and chlorophyll levels were monitored for...
Technical Report
Full-text available
Three linked workshops were held at the 4th IUCN Conservation Congress in Barcelona, Spain, in October 2008. The common theme among the workshops was the use of resilience approaches in conserving coral reefs. One workshop was focused on the science of resilience assessment, the second on applying resilience principles in Marine Protected Area Mana...
Technical Report
Full-text available
The objective of this report is to highlight the critical role of the oceans and ocean ecosys­ tems in maintaining our climate and in assisting policy makers to mainstream an oceans agenda into national and international climate change initiatives. While emissions’ re­ ductions are currently at the centre of the climate change discussions, the crit...
Technical Report
Full-text available
This report outlines results of an International Union for the Conservation of Nature (IUCN) assessment of the resilience to climate change of Pemba’s coral reefs. The coral reefs of Pemba, Tanzania, are among the most diverse in East Africa. However, they are extremely vulnerable to climate change. Thirteen reef sites on western Pemba covering a r...
Technical Report
Full-text available
Ocean acidification is the change in ocean chemistry driven by the uptake of carbon, nitrogen and sulfur compounds by the ocean from the atmosphere. Oceans are an important reservoir for CO 2 , absorbing a significant quantity (one-third according to Sabine et al. 2004) produced by anthropogenic activities and effectively buffering climate change....
Chapter
Full-text available
This study examines the bleaching responses of scleractinian corals at four sites in Kenya (Kanamai, Vipingo, Mombasa Marine Park and Nyali) representing two distinct lagoon habitats (relatively shallow and relatively deep). Bleaching responses were monitored for the general coral community and zooxanthella densities and chlorophyll levels were mon...
Chapter
Full-text available
Climate change will inevitably continue to cause degradation of coral reefs over coming decades (Hughes et al. 2003). The amount of damage depends on not only the rate and extent of change, but also on the ability of coral reefs to cope with change. Many MPA managers are asking, “What can we do about a large-scale issue such as climate change?” Res...

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Projects

Projects (6)
Project
To develop methodologies for assessing the ecological resilience of coral reefs, and to carry out resilience assessments in coral reefs around the world.
Project
Understanding the value of coastal ecosystems for climate change mitigation and carbon sequestration.
Archived project
Research on impacts of climate change on Maldivian coral reefs, their resilience to these impacts, and the ecosystem services they provide to people.