scholarly journals Rapidly increasing macroalgal cover not related to herbivorous fishes on Mesoamerican reefs

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2084 ◽  
Author(s):  
Adam Suchley ◽  
Melanie D. McField ◽  
Lorenzo Alvarez-Filip

Long-term phase shifts from coral to macroalgal dominated reef systems are well documented in the Caribbean. Although the impact of coral diseases, climate change and other factors is acknowledged, major herbivore loss through disease and overfishing is often assigned a primary role. However, direct evidence for the link between herbivore abundance, macroalgal and coral cover is sparse, particularly over broad spatial scales. In this study we use a database of coral reef surveys performed at 85 sites along the Mesoamerican Reef of Mexico, Belize, Guatemala and Honduras, to examine potential ecological links by tracking site trajectories over the period 2005–2014. Despite the long-term reduction of herbivory capacity reported across the Caribbean, the Mesoamerican Reef region displayed relatively low macroalgal cover at the onset of the study. Subsequently, increasing fleshy macroalgal cover was pervasive. Herbivorous fish populations were not responsible for this trend as fleshy macroalgal cover change was not correlated with initial herbivorous fish biomass or change, and the majority of sites experienced increases in macroalgae browser biomass. This contrasts the coral reef top-down herbivore control paradigm and suggests the role of external factors in making environmental conditions more favourable for algae. Increasing macroalgal cover typically suppresses ecosystem services and leads to degraded reef systems. Consequently, policy makers and local coral reef managers should reassess the focus on herbivorous fish protection and consider complementary measures such as watershed management in order to arrest this trend.

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Leor Korzen ◽  
Alvaro Israel ◽  
Avigdor Abelson

Herbivory is an important structuring factor in coral reefs, influencing seaweed abundance, competitive interactions between seaweeds and corals, and coral reef resilience. Despite reports of a drastic increase in the cover of benthic algae and turf dominancy in the coral reefs of Eilat, Red Sea, very little is known about the factors responsible for this phenomenon or the possible effects of herbivory on turf algae and coral recruits. Here, we examine the effects of herbivory by experimentally exposing turf algae and coral recruits to grazing activities of herbivorous fish and sea urchins. Using remote video cameras to document removal of algae and coral spats, we show that the main grazing impact is due to daily grazing by fishes, whereas the significant impact of sea urchins is mainly expressed in their adverse effect on the survival of coral recruits, with a relatively low effect on algal biomass. These findings contribute to our understanding of the factors influencing turf algae establishment and proliferation, and the survival of coral recruits on the coral reefs of Eilat. The clear differences between the impact of herbivorous fish and that of sea urchins, on the Eilat reefs, have critical implications for reef resilience and restoration measures.


PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2597 ◽  
Author(s):  
Diego Lirman ◽  
Stephanie Schopmeyer

Reef restoration activities have proliferated in response to the need to mitigate coral declines and recover lost reef structure, function, and ecosystem services. Here, we describe the recent shift from costly and complex engineering solutions to recover degraded reef structure to more economical and efficient ecological approaches that focus on recovering the living components of reef communities. We review the adoption and expansion of the coral gardening framework in the Caribbean and Western Atlantic where practitioners now grow and outplant 10,000’s of corals onto degraded reefs each year. We detail the steps for establishing a gardening program as well as long-term goals and direct and indirect benefits of this approach in our region. With a strong scientific basis, coral gardening activities now contribute significantly to reef and species recovery, provide important scientific, education, and outreach opportunities, and offer alternate livelihoods to local stakeholders. While challenges still remain, the transition from engineering to ecological solutions for reef degradation has opened the field of coral reef restoration to a wider audience poised to contribute to reef conservation and recovery in regions where coral losses and recruitment bottlenecks hinder natural recovery.


2020 ◽  
Vol 9 (1) ◽  
pp. 72-80
Author(s):  
Ary Hendri Pribadi ◽  
Suryanti Suryanti ◽  
Churun Ain

ABSTRAK Pulau Karimunjawa adalah salah satu objek destinasi wisata keindahan ekosistem terumbu karang. Kunjungan wisatawan di Karimunjawa dapat berdampak pada terumbu karang dan nilai ekonomi pariwisata. Penelitian ini dilaksanakan pada April-Mei 2019 di Kepulauan Karimunjawa, Kabupaten Jepara. Tujuan dari penelitian ini untuk mengetahui dampak pariwisata terhadap nilai status tutupan terumbu karang dengan menggunakan metode Line Intercept Transect (LIT) di Pulau Tanjung Gelam, Pulau Menjangan Besar dan Pulau Cemara Kecil serta nilai valuasi ekonomi pariwisata dengan menggunakan metode biaya perjalanan atau Travel Cost Method (TCM). Hasil yang didapatkan dari penelitian ini yaitu jumlah kunjungan wisatawan yang datang ke Pulau Karimunjawa meningkat sejak tahun 2016 hingga tahun 2018. Kondisi status tutupan terumbu karang yang diperoleh dalam kondisi baik dengan nilai karang hidup yang didapatkan pada Pulau Tanjung Gelam 61,6%, Pulau Menjangan Besar 70,8% dan Pulau Cemara Kecil 57,3%. Luasan terumbu karang pada tahun 2016 hingga tahun 2018 di Pulau Mejangan Besar dan Cemara Kecil mengalami penurunan. Sedangkan nilai valuasi ekonomi tahun 2016 sejumlah Rp.125.426.860,- 2017 dan 2018 sejumlah Rp.135.437.480,- dan Rp.156.932.039,-. Dampak wisatawan yang berkunjung tahun 2016-2018 pada valuasi ekonominya tiap tahunnya mengalami peningkatan. Hasil nilai valuasi ekonomi yang didapatkan pada penelitian ini,nilai rata-rata TCM pada wilayah Kabupaten Jepara Rp.1.111.023,- dan nilai ekonomi pertahunnya Rp.3.369.031.988,-. Rata-rata biaya perjalanan luar wilayah Kabupaten Jepara Rp.1.146.314,- dan nilai biaya pertahunnya Rp.12.324.171.938,-. Nilai total valuasi ekonomi dari dalam wilayah Kabupaten Jepara dan luar wilayah Kabupaten Jepara yaitu Rp.156.693.203.925,-. ABSTRACT Karimunjawa Island is one of the tourist destinations of the beauty of the coral reef ecosystem. Tourist visits in Karimunjawa can have an impact on coral reefs and the economic value of tourism. This research was conducted in April-May 2019 in the Karimunjawa Islands, Jepara Regency. The purpose of this study was to determine the impact of tourism on the status of coral cover status using the Line Intercept Transect (LIT) method on Tanjung Gelam Island, Menjangan Besar Island and Cemara Kecil Island and the economic valuation value of tourism using the travel cost method or the Travel Cost Method ( TCM). The results obtained from this study are the number of tourist arrivals to Karimunjawa Island increased from 2016 to 2018. The status of coral cover status obtained in good condition with the value of live coral obtained on Pulau Tanjung Gelam 61.6%; Pulau Menjangan Besar 70.8% and Pulau Cemara Kecil 57.3%. The extent of coral reefs in 2016 to 2018 on Pulau Mejangan Besar and Pulau Cemara Kecil declined. While the value of economic valuations in 2016 amounted to Idr.125,426,860,- 2017 and 2018 amounted to Idr.135,437,480,- and Idr.156,932,039,-. The impact of tourists visiting 2016-2018 on their economic valuations has increased each year. The results of the economic valuation obtained in this study, the average value of TCM in the Jepara Regency region is Idr.1,111,023, and the annual economic value is Idr.3,369,031,988. The average cost of trips outside the area of Jepara Regency is Idr.1,146,314, and the annual cost is Idr.12,321,171,938. The total value of economic valuations from within the Jepara Regency and outside the Jepara Regency is Idr.156,693,203,925. 


2021 ◽  
Author(s):  
Maike Iris Esther Scheffold ◽  
Inga Hense

Abstract. Understanding and determining where organic carbon (OC) ends up in the ocean and how long it remains there is one of the most pressing tasks of our time, as the fate of OC in the ocean links to the climate system. To provide an additional tool to accomplish this and other related tasks, we map and conceptualize OC pathways in a qualitative model. The model is complementary to existing concepts of OC processes and pathways which are based mainly on quantifications and observations of current states and dominant processes. Our model, on the contrary, presents general pathway patterns and embedded processes without focusing on dominant processes or pathways or omitting rare ones. By mapping, comparing, and condensing pathways and involved spatial scales, we define three remineralization and two recalcitrant dissolved organic carbon loops that close within the marine systems. Pathways that exit the marine system comprise inorganic atmospheric, OC atmospheric, and long-term sediment loops. With the defined loops and the embedded process options, the model is flexible and can be adapted to different systems, changing understanding or changing mechanisms. As such, it can help tracking pathway changes and assessing the impact of human interventions on pathways, marine ecosystems, and the oceanic organic carbon cycle.


2021 ◽  
Author(s):  
Artemi Cerdà ◽  
Enric Terol

High rates of soil erosion compromise sustainable agriculture. In rainfed agricultural fields, erosion rates several orders ofmagnitude higher than the erosion rates considered tolerable have been quantified. In Mediterranean rainfed crops suchas vineyards, almonds and olive groves, and in the new sloping citrus and persimmon plantations, the rates of soil lossmake it necessary to apply measures to reduce them to avoid collapse in agricultural production. Managements such asweeds, catch crops and mulches (straw and pruning remains) are viable options to achieve sustainability. This work appliesmeasurements through plots, simulated rainfall experiments and ISUM (Improved Stock-Unearhing method) to quantifythe loss of soil at different temporal and spatial scales in fields of traditional management (herbicide or tillage) and underalternative management (mulches and plant covers). The work carried out at the experimental station for the study of soilerosion in the Sierra de Enguera and those of Montesa and Les Alcusses provide information on erosion plots undernatural rain. Experiments carried out with simulated rain in fields of olive, almond, citrus, persimmon, vineyard and fruittrees report the hydrological and erosive response under low frequency and high intensity rains. And finally, the ISUMtopographic method report the impact of long-term management, from the plantation. The results indicate that the loss ofsoil is greater (x10-1000) in soils under traditional management (tillage and herbicide) due to the fact that they remain barefor most of the year. The use of straw mulch immediately reduces soil erosion by two orders of magnitude. Also mulchesfrom chipped pruned branches remains are very efficient but require more years to reduce soil loss. Weeds and catchcrops are very efficient in controlling erosion.


2021 ◽  
Vol 10 (2) ◽  
pp. 151-161
Author(s):  
Insafitri Insafitri ◽  
Eka Nurahemma Ning Asih ◽  
Wahyu Andy Nugraha

Wisata snorkeling terumbu karang di perairan pulau Gili Labak merupakan salah satu sektor wisata bahari yang sedang dikembangkan oleh pemerintah kebupaten Sumenep Madura sejak tahun 2014 hingga saat ini. Peningkatan jumlah wisatawan yang terjadi pada beberapa tahun terakhir dapat menimbulkan resiko tekanan dan kerusakan ekosistem terumbu karang di area snorkeling secara berkala. Penelitian ini bertujuan untuk mengetahui dampak kegiatan wisatawan sebelum, selama dan sesudah snorkeling terhadap ekosistem terumbu karang yang dikaji dengan mengetahui jenis karang yang mendominasi, status persentase tutupan terumbu karang serta potensi Dampak Wisata Bahari (DWB) snorkeling di lokasi wisata snorkeling pulau Gili Labak Sumenep. Persentase penutupan lifeform karang pulau Gili Labak khususnya di area snorkelling didominasi oleh karang hidup sebanyak 74% dan unsur abiotik sebesar 22%. Jenis karang yang mendominasi pulau Gili Labak adalah Acropora Branching sebesar 19,88% dan Coral Foliose sebesar 10,25%. Selama waktu 6 minggu pengamatan terjadi penurunan total karang sebesar 0,64% yang termasuk kategori rusak ringan, dimana sebagian besar kerusakan terjadi pada karang dengan bentuk pertumbahan branching misalnya Acropora Submassive dan Coral Submassive. Penurunan persen tutupan karang yang tinggi terjadi setelah kegiatan snorkeling (after) yang dilakukan oleh wisatawan. Analisa potensi Dampak Wisata Bahari (DWB) snorkeling pada terumbu karang di perairan Gili Labak selama 6 minggu pengamatan masuk dalam kategori rendah yaitu berkisar 0,052% hingga 0,085%. Faktor penyebab kecilnya nilai presentase Dampak Wisata Bahari (DWB) ini diduga karena waktu pengamatan cenderung pendek dan jenis karang yang mendominasi yaitu Acropora. Acropora memiliki kemampuan regenerasi lebih cepat dibandingkan jenis lainnya.  The snorkeling activity around coral reefs in the waters of Gili Labak is one of the marine tourism sectors that is being developed by the Sumenep Madura district government since 2014. Increasing number of tourists that occurs in recent years pose a risk of pressure and damage to coral reef ecosystems in the snorkeling area. This study aims to determine the impact of tourist activities before, during and after snorkeling on coral reef ecosystems that are studied by knowing the type of dominated coral, the percentage status of coral cover and the potential Impact of snorkeling at the snorkeling sites of the island of Gili Labak Sumenep. The percentage of coral cover in the island of Gili Labak especially in the snorkelling area is dominated by live coral ( 74%) and abiotic elements by 22%. Coral species that dominate the island of Gili Labak are Acropora Branching at 19.88% and Coral Foliose at 10.25%. During the 6-week observation there was a decrease in live coral cover by 0.64% which was categorized as minor damage, most of the damage occurred to branching   Acropora, sub-massive Acropora and Coral Sub-massive. The high percent decrease in coral cover occurred after snorkeling conducted by tourists. Analysis of the potential impact of snorkeling on coral reefs in the waters of Gili Labak for 6 weeks of observation is in the low category, ranging from 0.052% to 0.085%. The factor causing the small impact of Marine Tourism is presumably because the observation time tends to be short and the dominant coral species is Acropora. Acropora has the ability to regenerate faster than other types.


2017 ◽  
Author(s):  
Valeria Pizarro ◽  
Sara C Rodríguez ◽  
Mateo López-Victoria ◽  
Fernando A Zapata ◽  
Sven Zea ◽  
...  

Coral reefs supply millions of people with ecosystem goods and services, especially those living along tropical coastlines. Unfortunately, these ecosystems are disappearing at an alarming pace. In the Caribbean, the rate of coral loss is high (5.5 – 9.2% per year) and constant. In 2013, a healthy coral reef was discovered in one of the least expected places within the Colombian Caribbean: at the entrance of Cartagena Bay, a highly-polluted system that receives industrial and sewage waste, as well as high sediment and freshwater loads from an outlet of the Magdalena River (the longest and most populated river basin in Colombia). Here we provide the first characterization of Varadero Reef’s geomorphology and biological diversity. We also compare these characteristics with those of a nearby reference reef, Barú Reef, located in an area much less influenced by the described polluted system. Below the murky waters, we found high coral cover of 45.1% (± 3.9; up to 80% in some sectors), three species of lobster, eight of sea urchin, a fish community composed by 61 species from 24 families, and the typical zonation of a Caribbean fringing reef. All attributes found correspond to a reef that, according to current standards should be considered in "good condition". Current plans to dredge part of Varadero threaten the survival of this reef and could hinder efforts to uncover the underpinnings of this reef’s remarkable resilience. There is, therefore, an urgent need to describe the location and characteristics of Varadero as a first step towards gaining acknowledgement of its existence and garnering inherent legal and environmental protections.


2021 ◽  
Vol 4 (5) ◽  
pp. 152-164
Author(s):  
A. R. KELEKHSAEVA ◽  

The article examines poverty and inequality as serious long-term and widespread problems in society. Research on poverty has been mainly conducted from the perspective of economics, now the focus has shifted to psychological aspects with an emphasis on the causes and consequences of poverty. The overall economic disaster that COVID-19 will leave in Latin America and the Caribbean remains to be seen, but its impact on social well-being portends a bleak future. After seven years of slow growth, the region's GDP fell 5,3%, the largest drop in a century. According to a joint report submitted by the Economic Commission for Latin America and the Caribbean (ECLAC) and the Food and Agriculture Organization of the United Nations (FAO), the impact of the pandemic could plunge an additional 16 million people into extreme poverty in 2020, resulting in 83,4 million Hispanics will live in complete poverty. These organizations warn that hunger will be the biggest problem facing the region, where 53,7 million people are already surviving severely food insecure. The purpose of this study is to examine the relationship between poverty and inequality as economic categories in the context of their impact on the countries of Latin America. To do this, the authors examined the key factors affecting poverty and inequality, analyzed trends in poverty and inequality in Latin America and the Latin Basin. The article is based on research on poverty and inequality in macroeconomic theory. In particular, the works of Y. Amiel, F. Cowell, T. Buhard, P. Wizard, the study of socio-economic inequality and the fight against poverty – G. Babeuf, I. Bentham, J. M. Keynes, V. Paret, G. Spencer, L. Erhard, K. Arrow, D. Rocardo, A. Pigou and many others are devoted to the problem of inequality. Significant results of studies of poverty and welfare are given in the works of prominent foreign researchers: P. Townsend, A. Sen, D. Sachs, M. Orshan-sky, T. Marshall, F. Hayek, thanks to which the system of ideas about poverty was formed. The importance of poverty and its impact on government discourses, policies and programs has fueled much research on a Latin American scale. Publications on this topic have been rolled out over the past three decades and have created a veritable battlefield. Poverty reduction is a key development challenge facing Latin America and the Caribbean. Inequality is one of the historical problems in Latin America, one of the factors that most paralyzes the eco-nomic and social aspirations of most countries in the region. Poverty reduction can be understood in both a limited and a broad sense. The first involves a focus on programs and projects that target the poor – vocational training programs for low-income people, food stamps, productivity projects in the informal sector, and care for mothers and children in communities that do not have access to this service, etc. These programs are usually funded from so-called emergency funds and social investments, although they may also be specialized activities of the minis-tries or secretariats that make up the “social sector”. On the other hand, the broader definition of poverty reduction includes economic policies and traditional social policies (especially education and health). One of the main ways to solve this problem in the medium and long term obliges countries to move towards a universal basic income, giving priority to families with children and adolescents, and to maintain universal, comprehensive and sustainable social protection systems, increase their coverage as a central component of the new welfare state. A broad and lasting consensus and political commitment are required to make significant improvements in education, health and well-being. Unfortunately, some Latin American coun-tries have serious governance problems that hinder the effective functioning of democratic systems due to fragmentation and lack of policy consensus. For this reason, stability and continuity of economic and social policies are an indispensable element for the development of nations and the progress of peoples.


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