Can coral reefs survive to global heating?

Coral species from Great Barrier Reef in Australia
Photo by Simone Marques

This is a paramount question to answer nowadays, in the next 20 to 30 years to future generations about healthy and survive of coral reefs. Coral reefs are the most import aquatic ecosystem of the world that maintain higher biodiversity and keep a lot of resources to humankind. In last 30 years many coral species have been suffer with the sped up of global climate change and the consequences of global heating. The global heating bias to cause the coral bleaching in many species of coral and have changing the symbiosis tolerance with the zooxantelas and corals. Many species also became vulnerable to diseases going to death and future colonization by algae. However, some studies have showed some hopes about the resistance of coral reefs to thermal stress. Some experiments with Acropora species have indicated acclimatization of the coral species to thermal stress suggesting a physiological plasticity of the host (corals) and symbiotic components (bacterias and zooxantelas) playing an important role in response to ocean warming. 

To know more about the tolerance and resistance of coral reefs to thermal stress click on links bellow and enjoy 2 recent papers published by Bellantuono et al 2012.

Coral Thermal Tolerance: Tuning Gene Expression toResist Thermal Stress

Resistance to thermal stress in corals without changes in symbiont composition 

Marine debris

Example of Cleanup day Project in beaches of northeast coast of Brazil
Photo by Simone Marques

As a soup of plastic debris floating around our oceans... it's so sad to see most of debris produced by us going down to ocean and promote dangerous of aquatic ecosystems and species as marine turtles making mistakes with plastic debris as their preferential food is really a jellyfish. Most of this animals having suffering with this debris in our marine ecosystem and don't survive. This is not restricted about turtles but reaches marine birds, fishes, whales, dolphins and other marine organism that use or make mistake of their preferencial foods or refuges in their marine habitat. Also fisheries promote a lot of debris with fishnets and hooks where a lot of marine animals as birds, marine mammals and turtles can stay arrested and die.

Click on video bellow produced from Fantástico Report in Brazil and know more about the dangerous of debris in our marine ecosystems.

Mimicry in fishes

Aulostomus maculatus - trumpetfish mimicking with algae.
Photo by Simone Marques

Mimicry is a widely documented phenomenon in coral reef fishes, but the underlying relationships between mimics and models are poorly understood. Every fish have a special color in relation of your color's habitat as protection or opportunist behavior to feed or cheat their predator or prey. Also some fishes using some kind of colors or spots to communicate and distinguish yourself from another fish during their lifetime (juvenile to adult, female to male).

Here i suggest you 2 exciting papers about mimicry in reef fishes published by Sazima et al. 2005 and also Gagliano & Depczynski (2013).

 

Click in link bellow and enjoy know more about interesting features used by reef fishes..

Wolf in a sheep’s clothes: juvenile coney (Cephalopholis fulva)
as an aggressive mimic of the brown chromis (Chromis multilineata)

 Spot the Difference: Mimicry in a Coral Reef Fish

 

Endangered Species

Epinephelus itajara - goliath grouper: an endangered species in recovery after rescued in ponds of shrimps culture
(Photo by Simone Marques)

Several recent studies suggest that the current level of investment in conservation is far below what is needed to halt biodiversity loss. While there is general consensus within the conservation community that more resources are needed. After ECO 1992, the Convention on Biological Diversity (CBD) entered into force, with its objectives of conserving biological diversity, ensuring sustainable use of biological resources, and equitably sharing the benefits arising from the use of genetic resources. But this initiatives did not stop the loss of biodiversity with human actions around the natural resources of the planet.

IUCN, the International Union for Conservation of Nature

Now it's very important to you know more about our biodiversity and the list of endangered species. Every country has this list and the IUCN (International Union for Conservation of Nature) makes available on line the species around the world is endangered and monitoring with a great protocol of informations of each one of this species (http://www.iucn.org).

ICMBIO

Also in Brazil we having used this international tool to evaluate the endangered species through ICMBIO (Instituto Chico Mendes) where you can consult on line the list of endangered brazilian species (http://www.icmbio.gov.br/portal/biodiversidade/fauna-brasileira/lista-de-especies.html)

Rhincodon typus - A huge circumtropical marine fish species

Photo by Simone Marques

This is the major species of shark and can attain between 9 until 12 meters of length and 13 tons of weight. Rhincodon typus, is a planktivorous, filter- feeding elasmobranch that lives in tropical and subtropical oceans throughout the world and is the longest and heaviest of all fishes. The International Union for the Conservation of Nature lists the whale shark as ‘‘Vulnerable’’ in the 2010 Red List of Threatened Species. Population genetic structure has been investigated and some estimates of effective population size have been made, but the actual number of whale sharks inhabiting the world’s oceans is unknown.

Aggregations of whale sharks have been reported from in a several tropical locations around the world. These aggregations range from a few individuals to a few dozen and all are associated with locally high concentrations of zooplankton.  To know more about aggregation of whale shark clikc ane read the paper bellow published in Plos One by Venegas et al 2011.

An Unprecedented Aggregation of Whale Sharks, Rhincodon typus, in Mexican Coastal Waters of the Caribbean Sea

Hoolbox located in Mexical Coast is a good place to see this biggest species. Click in video bellow published by Blue World and enjoy this huge fish!

Giant Schooling of Mobula Ray

This is an amazing record of a giant schooling of mobula ray (Mobula sp.) in Baja California. It was a rare and huge event never has been registered before.

Click bellow and enjoy!

Ecological impacts of fishing

This is an important issue to read. Fishes are a great resource of protein and food to human kind, but with the increase of population and development of technology and economy the fisheries industries became a huge threaten for marine fishes populations and the destruction of many habitats in coastal and marine regions around the world. Read bellow the precious informations about it; published by Pauly et al. (2002) in Nature.

Simone Marques

Text extract from Pauly et al (2002). Towards sustainability in world fisheries

Historically, marine fishery resources were assumed to be almost limitless, and fishing was thought to have little impact on fish stocks and marine ecosystems. However, during recent decades, concern about the condition of fisheries has increased. Since 1989 world harvests have apparently leveled off. Many fisheries experts and commercial and recreational fishermen now recognize that fishing can have profound effects on marine fish stocks and the ecosystems they inhabit. Fishing and fisheries makes it abundantly clear that humans have had for thousands of years a major impact on target species and their supporting ecosystems. The fishing process became industrialized in the early nineteenth century when English fishers started operating steam trawlers, soon rendered more effective by power winches and, after the First World War, diesel engines. The Second World War added another ‘peace dividend’ to the industrialization of fishing: freezer trawlers, radar and acoustic fish finders. The fleets of the Northern Hemisphere were ready to take on the world. 

Rather the fisheries expanded their reach, both offshore, by fishing deeper waters and remote sea mounts, and by moving onto the then untapped resources of West Africa, southeast Asia, and other low-latitude and Southern Hemispheric regions. In 1950, the newly founded Food and Agriculture Organization (FAO) of the United Nations began collection of global statistics. Fisheries in the early 1950s were at the onset of a period of extremely rapid growth, both in the Northern Hemisphere and along the coast of the countries of what is now known as the developing world. Everywhere that industrial-scale fishing (mainly trawling, but also purse seining and long-lining) was introduced, it competed with small-scale, or artisanal fisheries. This is especially true for tropical shallow waters (10–100 m), where artisanal fisheries targeting food fish for local consumption, and trawlers targeting shrimps for export, and discarding the associated by-catch, compete for the same resource. Fisheries tend at first to remove large, slower-growing fishes, and thus reduce the mean TL of the fish remaining in an ecosystem. This eventually leads to declining trends of mean TL in the catches extracted from that ecosystem, a process now known as ‘fishing down marine food webs.

Fonte: Pauly et al. (2012). Towards sustainabilityin world fisheries. Nature 418: 689-695.

The principal, direct impact of fishing is that it reduces the abundance of target species. the past few decades have witnessed a growing awareness that fishes can not only be severely depleted, but also be threatened with extinction through overexploitation. Fisheries may also change the evolutionary characteristics of populations by selectively removing the larger, fast-growing individuals, and one important research question is whether this induces irreversible changes in the gene pool. Overall, this has implications for research, monitoring and management, and it points to the need for incorporating ecological consideration in fisheries management, as exemplified by the development of quantitative guidelines to avoid local extinctions

 Globally, 75% of coral reefs occur in developing countries where human populations are still increasing rapidly. Although coral reefs account for only 0.1% of the world’s ocean, their fisheries resources provide tens of millions of people with food and livelihood. Clearly, maintaining the biodiversity that is a characteristic of healthy reefs is the key to maintaining sustainable reef fisheries. Yet coral reefs throughout the world are being degraded rapidly, especially in developing countries. Concerns regarding overexploitation of reef fisheries are widespread. The entry of new, non-traditional fishers into reef fisheries has led to intense competition and the use of destructive fishing implements, such as explosives and poisons, a process known as ‘malthusian overfishing. Another major problem is the growing international trade for live reef fish, often associated with mobile fleets using cyanide fishing, and targeting species that often have limited ranges of movements. This leads to serial depletion of large coral reef fishes, notably the humphead wrasse (Cheilinus undulatus Labridae), groupers (Serranidae) and snappers (Lutjanidae), and to reefs devastated by the cyanide applications.

Cheilinus undulatus. Photo by Simone Marques

These fisheries, which destroy the habitat of the species upon which they rely, are inherently unsustainable. It can be expected that they will have to cease operating within a few decades, that is, before warm surface waters and sea-level rise overcome what may be left of the world’s coral reefs.

Rebuilding of marine systems is needed, and we foresee a practical restoration ecology for the oceans that can take place alongside the extraction of marine resources for human food. Reconciling these apparently dissonant goals provides a major challenge for fisheries ecologists, for the public, for management agencies and for the fishing industry.

Given the high level of uncertainty facing the management of fisheries, which induced several collapses, it has been suggested by numerous authors that closing a part of the fishing grounds would prevent overexploitation by setting an upper limit on fishing mortality. Marine protected areas (MPAs), with no-take reserves at their core, combined with a strongly limited effort in the remaining fishable areas, have been shown to have positive effects in helping to rebuild depleted stocks. In most cases, the successful MPAs were used to protect rather sedentary species, rebuild their biomass, and eventually sustain the fishery outside the reserves by exporting juveniles or adults. Although migrating species would not benefit from the local reduction in fishing mortality caused by an MPA, the MPA would still help some of these species by rebuilding the complexity of their habitat destroyed by trawling, and thus decrease mortality of their juveniles.

To know more read the paper: Pauly et al. (2012). Towards sustainability in world fisheries. Nature 418: 689-695.

  

InForMar Eletronic Magazine

InForMar Eletronic Magazine

by Simone Marques

Click in InForMar Eletronic Magazine now and access now the new edition of a great brazilian electronic magazine with open access to enjoy. This magazine is a special way to display notices about marine ecosystems for everyone and if you is brazilian or read and write portuguese you can participate in several reports of this magazine.

Read and share with your friends.

Hermaphroditism in reef fishes

 

 

Photos by Simone Marques

HERMAPHRODITISM

A   TALE   OF   TWO   SEXES

by Leonard Ho

(Reefscapes.net © 2002)

A hermaphrodite is defined as any individual organism that possesses both male and female reproductive organs during their life span.  The main advantage of hermaphroditism is the assurance of a reproductive partner.  Although hermaphroditism is quite common in invertebrates and plants, it is an exceedingly rare occurrence in vertebrates.  Hermaphroditism in mammals and birds are almost always a pathological condition (often leading to infertility).  Only in Perciforms (fish) does hermaphroditism occur naturally and in high frequency.

Hermaphrodites are divided into two main categories: synchronous hermaphrodites, and sequential hermaphrodites.  In the synchronous hermaphrodites, organisms possess both active male and active female reproductive organs at the same time.  In sequential hermaphrodites, both male and female reproductive organs may be present, but only one is active and viable at any given time. 

Synchronous, or simultaneous hermaphrodites in reef fish are relatively atypical.  A few Serranids (sea basses, e.g. Serranus sp.) and Hamlets are known synchronous hermaphrodites.

Sequential hermaphrodites are so named because they are capable of transforming from one sex to another.  Theses transformations entail a full conversion of gonads from one sex to another. The gonads of sequential hermaphrodites possess the genetic information to produce both male and female reproductive organs, but only the dominant gene is expressed at any give time. Different cues – varying from species to species – may induce sex changes.

Sequential hermaphrodites are further categorized into two main categories:protogynous and protandrous.  Protandrous hermaphrodites are those that develop into males first, then possibly to females.  Protogynous hermaphrodites are the exact opposite, with juveniles first developing female reproductive organs that may possibly change into male reproductive organs in select circumstances.  It should be noted that hermaphrodites do not necessarily have to change sexes, but by definition, are capable of this feat.

Protandrous hermaphrodites are the rarer of the two types.  Pomacentrids (damselfish) are the most famous of these hermaphrodites.  For example, clownfish of the genus Amphiprion live in communities that consist of of one dominant female specimen and several smaller male (or asexual juvenile) specimens.  If the female should be removed, a male will convert to a female, insuring a reproductive partner for the community.

Protogynous hermaphrodites are most often haremic fish.  These fish form monoandric harems comprising of 1 male overseeing numerous females for life.  The two primary responsibilities of the male are to defend its territory against other conspecific males, and to court and fertilize females of its territory.  If the male should die (either of natural causes or conflict-related mortality), the dominant female of the harem will undergo a sex change from female to male.  This sex change may take as little as 5 days.  The new male will then resume the full responsibilities of the previous male until he should die.  Protogynous hermaphrodites that form harems include the wrasses of the genus Cirrhilabrus and Paracheinlinus, Dwarf Angelfish of the genus Centropyge, and Anthias (e.g.Pseudoanthias sp.).

Some protogynous fish do not form harems, but may form pairs.  The dottybacks (Pseudochromis sp.) are presumably protogynous hermaphrodites that fall under this category.

There are also sequential hermaphrodites that waver between sexes with no discernable order. The sexes of these fish are often determined by the ratio of sexes in an immediate community. These types of hermaphrodites include numerous gobies.

International Day for Biological Diversity 2014

International Day for Biological Diversity 2014

The United Nations has proclaimed May 22 The International Day for Biological Diversity (IDB) to increase understanding and awareness of biodiversity issues. When first created by the Second Committee of the UN General Assembly in late 1993, 29 December (the date of entry into force of the Convention of Biological Diversity), was designated The International Day for Biological Diversity. In December 2000, the UN General Assembly adopted 22 May as IDB, to commemorate the adoption of the text of the Convention on 22 May 1992 by the Nairobi Final Act of the Conference for the Adoption of the Agreed Text of the Convention on Biological Diversity. This was partly done because it was difficult for many countries to plan and carry out suitable celebrations for the date of 29 December, given the number of holidays that coincide around that time of year.

Knows more: http://www.cbd.int/idb/

Video Ocean Overview

Comments by: Simone Marques

This is a great video of 7 minutes made by National Geographic to enjoy. You will understand the precious life and biodiversity of the oceans from marine microorganism to giant marine mammals. Although most of Earth Planet is composed by salt water mainly, the wide marine biodiversity is threatened by human actions destroying many habitas through fisheries, pollution, diseases and exploration of natural resources. This video is a time to think about what human kind is doing with your marine ecosystems.

Parrotfish Help Keep Coral Reefs Colorful

Video Parrotfish

Photo by David Doubilet

Environmental Initiatives

Environmental Initiatives

Starving Sea Lion Pups Show Why It's Important to Conserve Forage Fish

Author(s)

Paul Shively

Author(s) Description

Manager, U.S. Oceans, Pacific

-

When hundreds of abandoned sea lion pups began appearing on California beaches in early 2013, the public was justifiably alarmed. Wildlife rescue centers sprang into action, feeding and tending to the emaciated animals. Many people wondered about the cause.

Federal authorities announced the probable answer last week: a lack of high-nutrient prey fish, commonly known as forage fish that are a staple in the sea lions’ diet.

Researchers found little evidence of infectious disease or toxins affecting the 1,600 pups. Instead, it appears that lactating females were unable to nurse their offspring because they were undernourished themselves because of the decline in oil-rich forage fish such as Pacific sardines. The investigation was funded by public and private partners, including the Waitt Foundation. Fishermen discovered an absence of sardines early in the year, but the effect on the broader marine ecosystem was not readily apparent to the general public until emaciated sea lion pups began to appear.

“When the fishermen say there’s no sardines, what does that mean? Why should we care?” said Dr. Stephanie Venn-Watson, a veterinary epidemiologist with the National Marine Mammal Foundation who chairs a working group that examines unusual die-offs of marine mammals in the United States . “When people see 1,600 starving sea lion pups on the beach, then they can see why it matters.”



The decline in sardines — and the effect on apex predators like sea lions—starkly illustrates the importance of these forage fish to the ecosystem along the West Coast of the United States. It’s essential that fishery managers do everything they can to maintain a diversity and abundance of forage fish. Sardine populations rise and fall with natural fluctuations in ocean conditions, but fishing can exacerbate these swings so fisheries managers need to reduce commercial catches when sardines decline, as they are right now.

In recent months, the Pacific Fishery Management Council has sharply curtailed catch limits for sardines. The council set a relatively conservative limit of just over 23,000 tons of sardines for the season beginning July 1, a steep decline from the 66,000-ton limit during the last full season. Fishery managers would be wise to closely monitor sardines in the months ahead, and be willing to cut the catch if the population dwindles any further.

The plight of starving sea lion pups demonstrates that many species of ocean fish and wildlife depend on having enough forage fish to eat.

- See more at: http://www.pewenvironment.org/news-room/opinions/starving-sea-lion-pups-show-why-its-important-to-conserve-forage-fish-85899545301?utm_campaign=2014-05-22%20Latest%202.html&utm_medium=email&utm_source=Eloqua#sthash.k9RPmAyE.dpuf