I am a marine ecologist, dedicated to the promotion of marine conservation and restoration, through research and planning, and working as a consultant for governmental and non-governmental organizations worldwide (pro bono). My major concern is how to halt the rapid degradation of marine ecosystems and their essential services to humans. Likewise, I am working on solutions for sustainable exploitation of the sea as a source of food and as an alternative livelihood basis for fishermen and other ocean stakeholders, via environmentally sound aquaculture and responsible tourism (“eco-tourism”).
Prof. Avigdor Abelson
Basic and Applied Research Interests
- Coral Reef Restoration (CRR)
- Human impacts on marine ecosystems
- Artificial Reefs (ARs) and Fish Aggregating Devices (FADs): planning, design and implementation
- Restoration Ecology: holistic restoration of marine ecosystems; Settlement and recruitment of benthic marine organisms
- Marine conservation and Marine Protected Areas (MPAs)
- Sustainable aquaculture: Integrated Multi-Trophic Aquaculture (IMTA); Spirulina culture
- Coral reef ecology
- Marine bioinvasion – invasion and introduction of exotic marine organisms and their environmental impact on marine communities
- Tropical seamounts restoration and conservation
- Manta ray research and conservation
Turning degraded coral islands into sustainable social-ecological systems: A holistic approach
Anthropogenic activities exert diverse ecological stressors on the environment, in most, if not all, locations on the planet, and which in many cases are not directly sensed by humans. Nevertheless, there are numerous unfortunate circumstances where human-derived environmental problems adversely affect people and create stories of misery and helpless societies. Such is the tragedy of millions of people living on ecologically-degraded islands and coastal environments, whom are exposed to harsh conditions of insufficient, and often polluted, water and food supplies, preventing them of a healthy life and posing on them severe survival challenges. In many coastal locations, this hopeless situation is the outcome of over-exploitation and misuse of natural resources (e.g. over-fishing, habitat destruction and untreated sewage).This project applies a holistic approach, which considers all the interlinked elements of a coastal environment, i.e. terrestrial ecosystems-groundwater-coastal ecosystems-humans, applies and tests it on an isolated, small island the sub-systems of which can be better controlled. The idea is to reverse the declining trend of ‘degraded islands’ (including the island proper and its surrounding coastal ecosystems), by directly targeting manageable stressors (e.g. sewage, siltation, over-fishing), together with ecological restoration interventions and the creation of alternative livelihoods for local stakeholders. This holistic concept of the ‘Sustainable Island’ project offers a well-defined approach to saving numerous ‘small, low-laying islands’, many of which, beyond their poor ecosystem services and inability to support their inhabitants, are already at risk of drowning.
Coral Reef Restoration
Identifying the causes (stressors) that lead to the degradation of coral reefs is the first important step in the restoration process. There are several different states of degraded coral reefs that may warrant the need for restoration interventions, including structurally destroyed reefs (i.e. reduced to rubble), reefs with high reef-building coral cover, but very low fish biomass, reefs with high macroalgal and/or turf-algae cover, or high cover of non-reef building invertebrate taxa (e.g. notably sponges). These extreme states require different restoration tools and approaches, and in most cases it is essential to apply an integration of several complimentary methods, such as coral transplantation (‘coral-reef gardening’), enhancing structural complexity and grazer reintroduction. The induced recovery of coral reefs should be determined and implemented based on the reef state and target recovery features (e.g. reef structural complexity, live cover of reef-building corals, coral and fish recruitment, or herbivorous fish biomass). Regardless of causalities, a common approach to the problem of degraded ecosystems is a symptom-targeted restoration approach, which does not consider the interlinked nature of the problem. Restoration of degraded reefs, for instance, is often ‘remedied’ by the transplantation of corals (‘reef-gardening’), which is often applied as the sole restoration intervention, with no consideration of the reef state or the cause(s) of degradation. Our restoration projects aim to apply a holistic approach to the restoration process, through the identification of stressors affecting coral reefs, alleviation or removal of these stressors and implementation of appropriate restoration tools, if needed. Such approach, we believe, can achieve effective resiliency and longevity of each coral reef.
Global coral reefs are continuing to decline due to natural and anthropogenic disturbances (e.g. pollution, habitat destruction, over-fishing, and climate change), which pose a threat to the biodiversity of coral reefs, ecological functions, and ecosystem services. At present, approximately 75% of the world’s coral reefs are considered under threat due to destructive human impacts. One suggested way to rehabilitate coral reefs and compensate declined ecosystem services is the use of artificial reefs (ARs), which can enhance coral reef complexity, stabilize the reef structure, encourage the recruitment of larval reef fish, and provide alternative fishing grounds or dive sites. Our artificial reef projects are designed to examine the effects of different factors on the supply of organisms, either as larvae (via recruitment) or as adults, and spillover from artificial structures to natural reefs. We hope to be able to explicitly show how ARs promote larval recruitment, spillover, and enhanced recovery of natural reefs; and to shed light on the tremendous potential of artificial reefs as the foundation for compensation of ecosystem services, notably food supply and ecotourism-based livelihoods.
Tropical seamounts as ecological refugia
Seamounts may hold keys to improving conservation of coral reefs, pelagic megafauna species, and sustainable fishing. Seamounts are one of the most abundant and rich ecosystems in the sea, created from a mountain rising from the ocean floor or sinking islands. The raised position of seamounts in the water column, and consequent unique underwater currents, make them a prime attraction for fish, plankton, corals and other marine creatures. Tropical seamounts serve as aggregation sites for pelagic megafauna species such as manta rays, which are attracted to the abundance of food and cleaning stations (sites where large marine animals congregate to be cleaned by cleaner fish). This makes seamounts a coveted fishing ground for fishermen who exploit these extraordinary habits, which is leading to the deterioration of coral reefs and declining stocks of rare fish species. The goal of this study is to promote science-based fishery and conservation management of reef fish, coral reefs, and manta rays in seamounts, through an integration of conservation measures, education, ecotourism projects, and collaboration with local stakeholders. We believe that extending protection to deep seamounts could provide a refuge for coral reefs and marine animals affected by local stressors and global climate changes.
Sustainable Aquaculture – Integrated Multi-Trophic Aquaculture
Modern aquaculture provides an important answer for the increasing demand of food from the ocean worldwide; however its large operative dimensions and fast expansion is leading to significant environmental concerns. A prominent problem of aquaculture operations is the surplus discharge of organic matter from monoculture (aquaculture of a single species) and the leeching of dissolved nutrients into the environment. This can negatively affect natural ecosystems, causing habitat modifications, poor water quality, coastal eutrophication, and anoxic areas (“Dead Zones”). One solution to unsustainable aquaculture practices is based on traditional methodology, used for centuries in Asia, called Integrated Multi-Trophic Aquaculture (IMTA). “Integrated” refers to a close synergetic cultivation of several species, while “Multi-trophic” implies the different species occupying varying trophic levels. IMTA advocates for the integration of fed species such as finfish, with inorganic and organic extractive species like seaweeds (primary producers) and shellfish (filter feeders). This allows the waste material of one species to serve as a viable resource for another (e.g. organic fertilizer), creating an ecologically balanced, sustainable man-made system. By integrating locally important species, using novel IMTA designs, we can create a sustainable solution to the perpetual demand in global food markets, while even enhancing the conditions and nutritional value of the aquaculture species.
Spirulina cultivation in seawater: A new approach to fight malnutrition in poor coastal communities
Malnutrition and non-sustainable food acquisition are major challenges faced by many poor communities in the world. Cultivation of Spirulina (a microalga) in seawater may provide a sound solution in various coastal areas, as it contains high concentrations of protein, vitamins and minerals, which are deficient in the current diet of many communities. Together with "Algae Smart ltd" we are developing a handy, efficient Spirulina cultivation system, which will be based on seawater as the culture media and powered by solar energy. Hence, culturing the nutritious microalga will not require the use of diluted or pure freshwater, which is scarce in many areas, or grid electricity. The idea is to disseminate the system among poor coastal communities in developing countries for their own use and consumption, which may help fighting malnutrition and the consequent health and kids’ development challenges.
For a full list of publications and a more detailed research theme, please read here.
Abelson, A., R. Olinky, S. Gaines. 2005. Coral recruitment to the reefs of Eilat, Red Sea: temporal and spatial variation, and possible effects of anthropogenic disturbances. Mar. Poll. Bull. 50: 576–582.
Abelson, A. 2006. Artificial reefs versus coral transplantation as restoration tools for mitigating coral reef deterioration: benefits, concerns and proposed guidelines. Bull. Mar. Sci. 78; 151-159.
Abelson, A. and S. Gaines. 2006. A call for a standardized protocol of coral recruitment research and outlines for its conception. Mar. Poll. Bull. Dec;50(12):1745-8.
Pasternak, Z., B. Blasius, Abelson A. and Achituv Y., 2006. Host-finding behaviour and navigation capabilities of symbiotic zooxanthellae. Coral Reefs 25:201-207.
Pasternak, Z., A. Diamant, Abelson A. 2007. Co-invasion of a Red Sea fish and its ectoparasitic monogenean, Polylabris cf. mamaevi into the Mediterranean: observations on oncomiracidium behavior and infection levels in both seas. Parasitology Research 100:721-727.
Ben-Tzvi, A. Abelson, S. D. Gaines, M. S. Sheehy, G.L. Paradis and M. Kiflawi. The inclusion of sub Detection Limit (DL) LA-ICPMS data, in the analysis of otolith microchemistry by use of a "Palindrome Sequence Analysis" (PaSA). Limnol. Oceanogr. – methods 5:97-105.
Shaish, L., A. Abelson and B. Rinkevich. 2007. Branch to colony trajectory in a modular organism: Pattern formation in the Indo-Pacific coral Stylophora pistillata. PLoS One 7:e644(1-9)
Ben-Tzvi, M. Kiflawi, H. Gildor and A. Abelson. 2007. Possible effects of downwelling on the recruitment of coral-reef fishes to the Eilat coral reefs. Limnol. Oceanogr. 52:2618-2628.
Zvuloni, A., O. Mokady, G. Bernardi, S. Gaines, A. Abelson. 2008. Local scale genetic structure in coral populations in Eilat, Red Sea: an indication of selection? Mar. Poll. Bull. 56: 430-438.
Ben-Tzvi, O., M. Kiflawi, S. D. Gaines, M. Al-Zibdah, M. S. Sheehy, G.L. Paradis and Abelson, A. 2008. Tracking recruitment pathways of Chromis viridis in the Gulf of Aqaba using otolith chemistry. Mar. Ecol. Prog. Ser. 359: 229-238.
Ben-Tzvi, O., A. Abelson, O. Polak and M. Kiflawi. 2008. Habitat selection and the colonization of new territories by Chromis viridis. J. Fish Biol., 73:1005-1018.
Ben-Tzvi, M. Kiflawi, O. Polak and A. Abelson. 2009. The effect of adult aggression on habitat selection by settlers of two coral-dwelling damselfishes. PLoS One 4:e5511(1-8).
Siboni, N., S. Martinez, A. Abelson, A. Sivan and A. Kushmaro. 2009. Conditioning film and initial biofilm formation on electrochemical CaCO3 deposition on a metallic net in the marine environment. Biofoul. 25: 675–683
Bahartan, K., M. Zibdah, Y. Ahmed, A. Israel, I. Brickner and A. Abelson. 2010. Algal dominancy in coral reefs: A sign of reef degradation in the Eilat reefs (Gulf of Aqaba, Red Sea). Mar. Poll. Bull. 60: 759-764
Goren, M., G. Lipsky, E. Brokovich and A. Abelson. 2010. A ‘flood’ of alien cardinal fishes in the eastern Mediterranean - first record of the Indo-Pacific Cheilodipterus novemstriatus in the Mediterranean Sea. Aquatic Invasions 5: S49-S51.
Ben-Tzvi, O., M. El-Zibdah, V. Bresler, Y. Jamal and A. Abelson. 2011. Coral reef monitoring: Examination of the reliability of coral community indices based on comparisons with cytological tests. J. Mar. Sci. art id 151268, doi:10.1155/2011/151268
Korzen, L.S., A. Israel and A. Abelson. 2011. Herbivory Effects on Turf Algae and Coral Recruits: Implications of Fish versus Sea-Urchin Grazing on Coral Reef Resilience. J. Mar. Sci. art id 960207, doi:10.1155/2011/960207.
Ben-Tzvi, O., Abelson, A., Gaines, S. D., Bernardi, G., Beldade, R., Sheehy, M. S., Paradis, G. L., and M. Kiflawi. 2012. Evidence for Cohesive Dispersal in the Sea. PLoS ONE, 7(9), e42672. doi:10.1371/journal.pone.0042672
Keshavmurthy, S., et al. (incl. A. Abelson). 2013. DNA barcoding reveals the coral “laboratory-rat”, Stylophora pistillata encompasses multiple identities. Scientific Reports 3:1–7. doi:10.1038/srep01520
Martinez, S. and A. Abelson. 2013. Coral recruitment: The critical role of early post-settlement survival. ICES J. Mar. Sci. doi:10.1093/icesjms/fst035
Korzen, I.N. PulidindI, A. Israel, A. Abelson and A. Gedanken. 2015. Single step production of bioethanol from the seaweed Ulva rigida using sonication. RSC Advances, 5:16223-16229.
Korzen, L. Y. Peled, S. Zemah Shamir, M. Shechter, A. Gedanken, A. Abelson and A. Israel. 2015. An economic analysis of bioethanol production from the marine macroalga Ulva (Chlorophyta). Technology 3:114. DOI: 10.1142/S2339547815400105
Korzen, L., Pulidindi, I. N., Israel, A., Abelson, A., and Gedanken, A. 2015. Marine integrated culture of carbohydrate rich Ulva rigida for enhanced production of bioethanol. RSC Advances, 5:59251-59256.
Yeruham, E., G. Rilov, M. Shpigel and A. Abelson. 2015. Collapse of the echinoid Paracentrotus lividus populations in the Eastern Mediterranean - result of climate change? Scientific Reports 5: 13479. doi: 10.1038/srep13479
Korzen, L., A. Abelson and A. Israel. 2015. Growth, protein and carbohydrate contents in Ulva rigida and Gracilaria bursa-pastoris integrated with an offshore fish farm. Journal of Applied Phycology (accepted; online).
Abelson, A., Halpern, B.S., Reed, D.C., Orth, R.J., Kendrick, G.A., Beck, M.W., Belmaker, J., Krause, G., Edgar, G.J., Airoldi, L., Brokovich, E, France, R., Shashar, N., de Blaeij, A., Stambler, N., Salameh, P., Shechter, M. and Nelson, P. 2016. Upgrading Marine Ecosystem Restoration Using Ecological–Social Concepts. BioScience 66(2):156-163.
Obolski, U., L. Hadany and A. Abelson. 2016, Potential contribution of fish restocking to the recovery of deteriorated coral reefs: an alternative restoration method? PeerJ 4:e1732; DOI 10.7717/peerj.1732
Crane, N. L., M. J. Paddack, P. A. Nelson, A. Abelson, J. Rulmal, and G. Bernardi. 2016. "Corallimorph and Montipora Reefs in Ulithi Atoll, Micronesia: documenting unusual reefs." Journal of the Ocean Science Foundation 21: 10-17.
Abelson, A., P. Nelson, G. Edgar, N. Shashar, D. Reed, J. Belmaker, G. Krause, M. Beck, E. Brokovich, R. France, S. Gaines. 2016 Expanding marine protected areas to include degraded coral reefs. Conserv. Biol. 30 (6): 1182–1191 http://onlinelibrary.wiley.com/doi/10.1111/cobi.12722/abstract
Abelson, A, U. Obolski, P. Regoniel, L. Hadany. 2016. Restocking of herbivorous fish populations as an ecological-social restoration tool in coral reefs. Frontiers Mar. Sci. 3, 138. https://doi.org/10.3389/fmars.2016.00138
Crane, N., M. Paddack, P. Nelson, A. Abelson, K. Precoda6, J. Rulmal and G. Bernardi. 2017. Atoll-scale patterns in coral reef community structure: Human signatures on Ulithi Atoll, Micronesia. PLoS One, 12(5), p.e0177083.
Yanovsky, R., P. Nelson and A. Abelson. 2017. Structural complexity in coral reefs: evaluation tools and spatial scales. Frontiers in Ecology and Evolution , 5, p.27.
Ashkenazi, D., A. Israel and A. Abelson. 2019. A novel two-stage seaweed IMTA (Integrated Multi-Trophic Aquaculture), Reviews in Aquaculture, 11(1), 246-262. https://doi.org/10.1111/raq.12238.
Yeruham, E., A. Abelson, G. Rilov, D.B. Ezra and M. Shpigel. 2019. Energy budget of cultured Paracentrotus under different temperatures. Aquaculture 501, 7-13.
Barr, Y. and A. Abelson. 2019. Feeding-cleaning trade-off: Manta ray "decision-making" as a conservation tool. Frontiers in Marine Science. https://doi.org/10.3389/fmars.2019.00088
Yanovski, R. and A. Abelson. 2019. Structural complexity enhancement as a potential coral-reef restoration tool. Ecological Engineering 132, 87-93.
Yeruham, E., M. Shpigel, A. Abelson and G. Rilov. 2019. Ocean warming and tropical invaders erode the performance of a key herbivore. Ecology. http://doi.org/10.1002/ecy.2925
Abelson, A. 2019. Are we sacrificing the future of coral reefs on the altar of the "climate change" narrative? ICES Journal of Marine Science, fsz226. http://doi.org/10.1093/icesjms/fsz226.