New chromadorid nematodes from Brazilian coral reefs: a taxonomic contribution to Chromadora Bastian, 1865

Zootaxa ◽  
2021 ◽  
Vol 5032 (1) ◽  
pp. 47-79
Author(s):  
PATRÍCIA FERNANDES NERES ◽  
PAULO JORGE PARREIRA DOS SANTOS ◽  
ANDRÉ MORGADO ESTEVES
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Sea Level ◽  
Species Identification ◽  
Benthic Fauna ◽  
Diagnostic Characteristics

A study involving experiments on a natural Brazilian coral reef, with the aim of assessing the impacts that may be caused by an increase in sea level on benthic fauna, showed that Chromadoridae Filipjev, 1917 was the most abundant and diverse family of Nematoda. Our results also showed that Chromadora Bastian, 1865 was the most abundant and diverse genus, represented by three species: C. serrambi sp. nov., C. pernambucana sp. nov. and C. macrolaimoides Steiner, 1915. Chromadora serrambi sp. nov. is the only Chromadora species where pre-cloacal supplements are absent. Chromadora pernambucana sp. nov. is differentiated by gubernaculum shape and by three supplements, of which two are cup-shaped (small and slightly sclerotized) and a pre-cloacal papilla very close to the cloaca. Chromadora macrolaimoides is very similar to specimens described previously. Here, we propose a grouping of species based on features considered to be most relevant for species identification and present it as an illustrated guide. The diagnostic characteristics of all species were considered, and following discussions, C. micropapillata was revalidated. Finally, the most relevant diagnostic characteristics for the differentiation of Chromadora species were highlighted.  

scholarly journals Measuring Sound at a Cold-Water Coral Reef to Assess the Impact of COVID-19 on Noise Pollution

2021 ◽  
Vol 8 ◽  
Author(s):  
Laurence H. De Clippele ◽  
Denise Risch
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Sea Level ◽  
Cold Water ◽  
Noise Pollution ◽  
Ecosystem Functions ◽  
Noise Levels ◽  
Level Height ◽  
Water Coral

This study compares the noise levels at the cold-water coral Tisler reef, before and after the closure of the border between Norway and Sweden, which occurred as a direct result of the COVID-19 pandemic. The Tisler reef is a marine protected area located under a ferry “highway” that connects Norway and Sweden. Cold-water coral reefs are recognised as being important hotspots of both biodiversity and biomass, they function as breeding and nursing grounds for commercially important fish and are essential in providing ecosystem functions. Whilst studies have shown that fishery, ocean warming, and acidification threaten them, the effects of noise pollution on cold-water coral reefs remains unstudied. To study the severity of noise pollution at the Tisler reef, a long-term acoustic recorder was deployed from 29 January 2020 until 26 May 2020. From 15 March COVID-19 lockdown measures stopped passenger vessel traffic between Norway and Sweden. This study found that the overall noise levels were significantly lower after border closure, due to reduced ferry traffic, wind speeds, and sea level height. When comparing the median hourly noise levels of before vs. after border closure, this study measured a significant reduction in the 63–125 Hz 1/3 octave band noise levels of 8.94 ± 0.88 (MAD) dB during the day (07:00:00–19:59:59) and 1.94 ± 0.11 (MAD) dB during the night (20:00:00–06:59:59). Since there was no ferry traffic during the night, the drop in noise levels at night was likely driven by seasonal changes, i.e., the reduction in wind speed and sea level height when transitioning from winter to spring. Taking into account this seasonal effect, it can be deduced that the COVID-19 border closure reduced the noise levels in the 63–125 Hz 1/3 octave bands at the Tisler reef by 7.0 ± 0.99 (MAD) dB during the day. While the contribution of, and changes in biological, weather-related and geophysical sound sources remain to be assessed in more detail, understanding the extent of anthropogenic noise pollution at the Tisler cold-water coral reef is critical to guide effective management to ensure the long-term health and conservation of its ecosystem functions.

scholarly journals Divergence of seafloor elevation and sea level rise in coral reef ecosystems

2017 ◽  
Vol 14 (6) ◽  
pp. 1739-1772 ◽  
Author(s):  
Kimberly K. Yates ◽  
David G. Zawada ◽  
Nathan A. Smiley ◽  
Ginger Tiling-Range
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Sea Level Rise ◽  
Sea Level ◽  
Anthropogenic Impacts ◽  
Regional Scale ◽  
Coastal Hazards ◽  
Carbonate Production ◽  
Coral Reef Ecosystems ◽  
Study Sites

Abstract. Coral reefs serve as natural barriers that protect adjacent shorelines from coastal hazards such as storms, waves, and erosion. Projections indicate global degradation of coral reefs due to anthropogenic impacts and climate change will cause a transition to net erosion by mid-century. Here, we provide a comprehensive assessment of the combined effect of all of the processes affecting seafloor accretion and erosion by measuring changes in seafloor elevation and volume for five coral reef ecosystems in the Atlantic, Pacific, and Caribbean over the last several decades. Regional-scale mean elevation and volume losses were observed at all five study sites and in 77 % of the 60 individual habitats that we examined across all study sites. Mean seafloor elevation losses for whole coral reef ecosystems in our study ranged from −0.09 to −0.8 m, corresponding to net volume losses ranging from 3.4  ×  106 to 80.5  ×  106 m3 for all study sites. Erosion of both coral-dominated substrate and non-coral substrate suggests that the current rate of carbonate production is no longer sufficient to support net accretion of coral reefs or adjacent habitats. We show that regional-scale loss of seafloor elevation and volume has accelerated the rate of relative sea level rise in these regions. Current water depths have increased to levels not predicted until near the year 2100, placing these ecosystems and nearby communities at elevated and accelerating risk to coastal hazards. Our results set a new baseline for projecting future impacts to coastal communities resulting from degradation of coral reef systems and associated losses of natural and socioeconomic resources.

Review Lecture - Living corals

1968 ◽  
Vol 169 (1017) ◽  
pp. 329-344 ◽  
Keyword(s):  
Coral Reef ◽  
Calcium Carbonate ◽  
Coral Reefs ◽  
Sea Level ◽  
Living Coral ◽  
Precise Nature ◽  
Functional Aspects

Coral reefs have a dramatic impact owing to their frequent vast extent; above sea level they may form the basis of inhabited islands while below the surface they constitute major hazards to navigation. Perhaps for this reason the precise nature of the animals primarily responsible for their creation tends to be overlooked. Literature on the ‘coral reef problem a matter of primarily geological and geographical concern, is far greater than that on corals themselves. It is as though these animals have become buried under the vast mass of the skeletons they secrete, of the calcium carbonate they extract from the sea to convert into aragonite. Perhaps even the beauty of living coral colonies distracts from consideration of the animal itself. In the hope of in some measure correcting the balance, this lecture is concerned solely with the animal, in particular with the functional aspects of structure together with development and ecology, all viewed from a broadly evolutionary standpoint.

4. The resulting structure—a reef

2014 ◽  
Author(s):  
Charles Sheppard
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Sea Level ◽  
Environmental Conditions ◽  
General Structure ◽  
Back Reef ◽  
Soft Corals ◽  
Basic Pattern ◽  
Geological Time ◽  
Episodic Growth

‘The resulting structure—a reef’ shows that coral reef profiles, composed of reef flats, reef crests, and reef slopes, are remarkably consistent. The general structure is complicated by shifts of sea level over geological time, so the basic pattern will have superimposed upon it evidence of episodic growth and erosion. The environmental conditions on the reef slope are ideal for most corals and other reef life including the soft corals and sponges, so this is where most species are found. The cryptic, or hidden, life of the coral reefs is discussed along with the rugosity of the corals, and the structure and life of the sand in the back reef area.

scholarly journals Divergence of seafloor elevation and sea level rise in coral reef regions

2016 ◽  
Author(s):  
Kimberly K. Yates ◽  
David G. Zawada ◽  
Nathan A. Smiley ◽  
Ginger Tiling-Range
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Sea Level Rise ◽  
Sea Level ◽  
Anthropogenic Impacts ◽  
Regional Scale ◽  
Coastal Hazards ◽  
Carbonate Production ◽  
Coral Reef Ecosystems ◽  
Study Sites

Abstract. Coral reefs serve as natural barriers that protect adjacent shorelines from coastal hazards such as storms, waves and erosion. Projections indicate global degradation of coral reefs due to anthropogenic impacts and climate change will cause a transition to net erosion by mid-century. Here, we provide a comprehensive assessment of the combined effect of all of the processes affecting seafloor accretion and erosion by measuring changes in seafloor elevation and volume for 5 coral reef ecosystems in the Atlantic, Pacific and Caribbean over the last several decades. Regional-scale mean elevation and volume losses were observed at all 5 study sites and in 78 % of the 59 individual habitats that we examined across all study sites. We estimate that 12 % to 65 % of seafloor elevation loss may be attributed to reduced carbonate production, bioerosion and carbonate dissolution and 35 % to 88 % may be attributed to physical erosion and export of sediment from these systems. Erosion of both coral-dominated substrate and non-coral substrate suggests that the current rate of carbonate production is no longer sufficient to support net accretion of coral reefs or adjacent habitats. We show that regional-scale loss of seafloor elevation and volume has accelerated the rate of relative sea level rise in these regions. Current water depths have increased to levels not predicted until near the year 2100, placing these ecosystems and nearby communities at elevated and accelerating risk to coastal hazards. Our results set a new baseline for projecting future impacts to coastal communities resulting from degradation of coral reef systems and associated losses of natural and socio-economic resources.

Concluding remarks

1978 ◽  
Vol 284 (999) ◽  
pp. 161-163
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Sea Level ◽  
Royal Society ◽  
Deductive Reasoning ◽  
Point Of View ◽  
Major Theme ◽  
Barrier Reef ◽  
Barrier Reefs ◽  
Coral Islands

The Great Barrier Reef Expedition of 1928-29 and the Royal Society and Universities of Queensland Expedition of 1973 are separated in time by only 44 years. In that period coral reef studies expanded greatly and the geomorphology of reefs and reef areas became a major theme of research. Up to 1928 it is almost true to say that no work had been done on coral islands, and the writings on reefs were almost entirely biological. W. M. Davis’s The Coral Reef Problem appeared in 1928. It was the first book that examined coral reefs from a geomorphological point of view. Davis made extensive use of deductive reasoning, but he did not examine, on the ground, the structure and formation of coral islands, although he travelled widely in coral regions and made great use of charts. He did, however, emphasize and discuss at length the importance of studying reefs in relation to the coast of the land they border. Thus he enlarged on the point, first made by Dana, that drowned valleys imply not only subsidence of the land they traverse but also of the foundation of the reefs in front of that land. This was a major contribution. Two other comments made by Davis are only of subsidiary importance - the unconformable contacts of reefs on the rocks on which they rest, and the disposal of detritus in lagoons, especially in subsiding areas. Davis’s conclusion was that Darwin’s theory of subsidence was the most convincing explanation of the way in which barrier reefs and atolls are formed. He also, rightly, acknowledged the force of Daly’s glacial control theory, but fluctuations of sea level in the Quaternary were regarded as relatively minor incidents in comparison with the much greater subsidence that was necessary to explain deep drowned valleys and the evidence of the Funafuti bore. Incidentally this bore and the much shallower one on Michaelmas Reef were the only ones that were made before 1928. Davis also demonstrated the significance of cliffing in the marginal belts and the general absence of cliffs within reefs in the truly coral seas. In short, up to about 1928 discussions on the origin of coral reefs were wholly theoretical; despite the swing towards Darwin’s hypothesis there were still supporters of the theories propounded by Murray, Agassiz, Gardiner and others.

Prominence of environmental and anthropogenic agents on the occurrence of coral reef bleaching syndrome and coral diseases

2024 ◽  
Vol 74 (10) ◽  
pp. 6139-2024
Author(s):  
MICHAŁ SCHULZ ◽  
ALEKSANDRA ŁOŚ ◽  
PATRYCJA SKOWRONEK ◽  
ANETA STRACHECKA
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Oil Spills ◽  
Global Scale ◽  
Ecological Processes ◽  
Coral Diseases ◽  
Rapid Changes ◽  
Anthropogenic Threats ◽  
Negative Factors ◽  
Main Relationship

Coral reefs are the most productive ecosystems on Earth. They ensure the conservation of biodiversity and are a live habitat for 25% of all marine organisms. The main relationship on the coral reef is the symbiosis between corals and algae from the genus Symbiodinium (commonly called zooxanthellae). The authors of this publication have characterized and described the factors limiting the occurrence of coral reefs, including: water temperature, salinity, access to sunlight, contamination, physicochemical and hydromechanical parameters of water. Moreover anthropogenic threats to coral reefs have been specified, including diving tourism, ecological disasters (e.g. oil spills) and the development of marine aquaristics. Rapid changes in the basic living conditions are dangerous for corals and their symbionts and may cause the unsuitability of the new environment resulting in diseases such as coral bleaching. Corals bleaching is a disease associated with the break of the coral and algae relationship which results in a coral reef death on a global scale. Awareness of these negative factors, often related to human activity, may allow us to better understand the ecological processes that are the basis of reef functioning and might enable us to prevent and oppose to the changes and ecological recessions of coral reefs.

scholarly journals Turbid Coral Reefs: Past, Present and Future—A Review

Diversity ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 251
Author(s):  
Adi Zweifler (Zvifler) ◽  
Michael O’Leary ◽  
Kyle Morgan ◽  
Nicola K. Browne
Keyword(s):  
Climate Change ◽  
Coral Reef ◽  
Coral Reefs ◽  
Environmental Change ◽  
Scientific Literature ◽  
Conservation Status ◽  
Climate Change Impacts ◽  
Geographic Range ◽  
Reef Complex ◽  
Sediment Input

Increasing evidence suggests that coral reefs exposed to elevated turbidity may be more resilient to climate change impacts and serve as an important conservation hotspot. However, logistical difficulties in studying turbid environments have led to poor representation of these reef types within the scientific literature, with studies using different methods and definitions to characterize turbid reefs. Here we review the geological origins and growth histories of turbid reefs from the Holocene (past), their current ecological and environmental states (present), and their potential responses and resilience to increasing local and global pressures (future). We classify turbid reefs using new descriptors based on their turbidity regime (persistent, fluctuating, transitional) and sources of sediment input (natural versus anthropogenic). Further, by comparing the composition, function and resilience of two of the most studied turbid reefs, Paluma Shoals Reef Complex, Australia (natural turbidity) and Singapore reefs (anthropogenic turbidity), we found them to be two distinct types of turbid reefs with different conservation status. As the geographic range of turbid reefs is expected to increase due to local and global stressors, improving our understanding of their responses to environmental change will be central to global coral reef conservation efforts.

Sign in / Sign up

Export Citation Format

Share Document