Pink beauty : boon or bane (flamingoes as bioindicators of doom)
22.08.2023
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Mr. Nirmal manna
514, M.Sc Zoology ,Part 2, Life processes, ,Paper 1,Ramnarain Ruia Autonomous College
Table of contents
Background…………………………………………………………………………..…………….…03
Flamingo biology…………………………..……………………………………………………….…04
……………Filter feeding………………………………………………………………..………….…05
……………Food stock ………………………………………………………………..…………….…07
……………Benefits as bioindicators …………………………………………….…………….…08
Sensitivity to pollution……………………………………………………………..…………….…08
….……… Mechanism of sensitivity…………………………………………………..………….…09
….……… the dilemma…………………………………………………………………..………….…11
Conclusion……………………………………………………………………………….………….…13
Bibliography………………………………………………………………………………...…………14
Reference……………………………………………………………….……………..…………….…14
S.P Mandali’s
Ramnarain Ruia Autonomous College
Matunga, Mumbai - 400019.
CERTIFICATE
This is to certify that Mr. Nirmal Manna of Masters of Science in Zoology, Ramnarain Ruia Autonomous College has satisfactorily completed and documented the assignment work of Zoology Paper RPSZOP301: Life processes during the Semester III of the class MSc part 2 of the year 2023-2024.
______________________ ______________________
Signature of Faculty in charge Head of Department
Date: 22/08/23
Background
Oceans rivers and lakes cover more than two thirds of the earth's surface and they teem with millions of creatures – creatures of different sizes and of strange and fantastic shapes. The flamingo population of India’s largest city has tripled. Is it thanks to sewage boosting the blue-green algae they feed on? There is an air of anxious excitement among the urban professionals At the moment it’s a great situation for the birds as They are an extremely gregarious species.
Water pollution is a growing environmental concern that has detrimental effects on aquatic ecosystems, human health, and biodiversity. Monitoring the health of aquatic environments is essential for effective pollution management. One innovative approach to assessing water quality is the use of bioindicators, organisms that respond sensitively to environmental changes. This assignment focuses on flamingoes (Phoenicopteridae) as bioindicators of water pollution, exploring their sensitivity to pollution, potential mechanisms, and the benefits of their use.
One of the aims of monitoring is to provide information for ecological assessment,
which can provide early warning of changes that could negatively affect species or
ecosystems. Since it is impractical to monitor all biological and physical components, a few of them can be used as indicators of wider conditions.Biological components chosen with this aim are called bioindicators.Several aspects of the ecology of waterbirds make them useful as bioindicators.First, waterbirds have been shown to track environmental variations, at short(months) and long (years) temporal scales, and at both species and community levels. Second, because many species are top predators and several contaminants often accumulate along the trophic chain, such species may be used as indicators of changes occurring at lower trophic levels.And third, either the waterbirds themselves or their prey are exploited by humans(e.g. hunting and fisheries), so that hunting bags of waterbirds may be indicative of productivity in nesting area or breeding parameters of birds may inform on fish stocks.
Though birds are popular subjects for research and monitoring, and long-term datasets of waterbird counts often provide a useful resource as indicators of ecological change.
However, different waterbird species undergo population fluctuations for different
reasons, and a thorough knowledge of the ecology of a given species is required if
trends are to be interpreted correctly. Waterbirds do not merely respond to environ-
mental change, they can also be the cause of change as their populations increase, due
to overgrazing or because they act as vectors of nutrients and contaminants. In some
cases birds may not respond to wetland characteristics in the same way as other
groups of organisms, in which case birds may not be considered as surrogates of other
organisms in biomonitoring programs. In other cases, however, birds can be reliable
indicators of nutrient status, fish stocks or the abundance of aquatic plants. As the
difficulties inherent in monitoring some groups of organisms (e.g. aquatic vegetation)
might be best avoided if a reliable indicator is available, in these last cases birds may
be considered as relatively easily measurable surrogates. When using waterbirds as
indicators, clear objectives for the monitoring programme are essential.
A flock of lesser flamingos captured wading and feeding along the shore area
Flamingo biology
Flamingos (Aves, Phoenicopteridae) are an ancient lineage of long-legged, microphagous, colonial wading birds. Although popularly misperceived as tropical species, flamingo distribution is more closely tied to the great deserts of the world and hypersaline lake sites than equatorial regions . Flamingos are filter feeders that thrive on halotolerant cyanobacterial blooms in mesohaline shallows of saline lakes worldwide. This creates the context between flamingos, mesohaline planktonic blooms, and saline lakes.
Worldwide, only six sites are used for breeding by the lesser flamingos: Lake Natron (Tanzania), Etosha Pan (Namibia), Makgadikgadi-Pan (Botswana), Kamfers Dam (South Africa), as well as two pans in the “Little Rann of Kachchh” (India). Recent estimates of lesser flamingos at the main distribution areas are as follows: 1.5–2.5 million in eastern Africa; 390,000 in northwestern India; 55,000-65,000 in southwestern Africa; and 15,000–25,000 in western Africa. The highest population densities occur in Kenya (1.5 million) and Tanzania (600,000) . Lesser flamingos are well adapted to the harsh conditions associated with living and breeding in hypersaline alkaline conditions. Worldwide, lesser flamingoes follow an itinerant lifestyle, ranging across their distribution areas searching for saline water bodies with appropriate cyanobacterial blooms. In the East African Rift, the flocks can travel up to 200 km a day between feeding and breeding sites, generally at geographically separate locations
Filter feeding
Flamingoes (both Greater and Lesser) pass water through their bill filters in two ways either by swinging their heads back and forth just below the water surface, so permitting the water to flow passively through the filters of their beak, or by more efficient and more usual system of an active beak pumping. The latter is maintained by a large and powerful tongue that fills a large channel in the lower beak. As it moves rapidly back and forth, up to four times a second, it drawing water and plankton through the beak filters on the backwards pull and expelling it on the forward drive. The tongue's surface also sports numerous denticles that scrape the collected food from the filters.
Head of the Greater Flamingo shown with the bill closed and tongue extended during the filtering stage of filter feeding (left), and with the bill open and tongue retracted during the intake stage (right). Note the large recurved spines on the flattened upper surface of the tongue used to retain food (middle), as well as the lamellae along the articulating edge of the uncut upper mandible (complementary structures are also present on the lower mandible, which has been cut away in this illustration to expose the mouth cavity). Water is forced from the mouth cavity during the filtering stage by the piston-like action of the large, fatty tongue.
Greater flamingoes feeding
Flamingo beaks have evolved into highly efficient plankton-extraction apparati that exploit the dense cyanobacterial populations periodically found in mesohaline lakes worldwide. The beak is unlike that possessed by any other bird group on earth; the affinity is more to the baleen of whales used to filter planktonic krill from the lit upper waters of the world's oceans. A flamingo beak houses a high volume water-filtering system made up of a piston-like tongue and hair-like structures called lamellae made up of rows of fringed platelets that line the inside of the mandible. In the lesser flamingo, the lamellae fibres have the appropriated spacing for capturing coiled filaments of Arthrospira.
Lamellar spacings are wider in the beaks of the greater flamingo than those in the beaks of the lesser flamingo, so these larger-sized birds are more generalist feeders of lake zooplankton. Thus, in any mesohaline lake where the two bird species feed and co-exist, they do not compete for the same food source. By swinging their upside-down heads from side to side just below the water surface and using the piston-like tongue to swish water through their lamella-lined beaks, flamingos can syphon the lake plankton into their gullets at phenomenal rates. Lesser flamingos can pump and filter as many as four beakfuls of plankton-rich water a second. This means some individuals filter upwards of 20,000 litres of water per day.
How the birds manage to cycle so much brackish to mesohaline waters, while maintaining their osmotic integrity, remains a mystery. When dense cyanobacterial blooms typify the rift lakes, each adult bird ingests around 72 g dry weight of Arthrospira per day. Rates of planktonic renewal in these rift lakes are incredibly high, and the required rates of biomass production by Arthrospira are spectacular.
food stock
They are mostly nocturnal feeders and will feed for up to 12-13 hours in a 24 hour period. The preferred planktonic food of the lesser flamingo is the planktonic cyanobacterium Arthrospira fusiformis (sometimes confused with the benthic cyanobacterium Spirulina platensis), which for much of an average year is the widespread phytoplankton component in Arthrospira has high levels of the red pigment phycoerythrin. So when ingested in large volumes, it accumulates in flamingo feathers to give the birds their world-famous colouration, hence the "flamingo connection." Once digested, the carotenoid pigment dissolves in fats, which are then deposited in the growing feathers. The same effect is seen when shrimp change colour during cooking due to carotenoid alteration. The amount of pigment laid down in the feathers depends on the quantity of pigment in the flamingo's diet. With beak design maximised to feed on Arthrospira, lesser flamingos have a more intense pink colour in their feathers than greater flamingos. The latter species sits higher in the Lake Nakuru food chain and so gets the slight pink tinge in its feather colour, mostly second-hand from the lake zooplankton, which also feeds on Arthrospira.
As well as possessing very high levels of phycoerythrin in its cytoplasm, Arthrospira is also unusual among the cyanobacteria in its unusually high protein content (some ten times that of soya). This species' high growth rate explains why Nakuru and Bogoria acme populations can support such spectacularly dense flamingo population levels.
They are filter feeders, which means they eat small organisms and detritus from the water. This makes them susceptible to pollutants, which can accumulate in their bodies.They are particularly sensitive to pollutants such as heavy metals, pesticides, and fertilizers. These pollutants can damage their feathers, bones, and organs, and can even kill them. The presence of flamingos in an area can be a sign that the water is polluted. The number of flamingos, their health, and their behavior can all be used to assess the level of pollution. For example, a decrease in the number of flamingos in an area may indicate that the water quality has declined. Similarly, flamingos with pale feathers or deformed bones may be a sign of pollution.
Benefits as Bioindicators
1. Early Warning System: Flamingoes' vulnerability to pollution allows them to serve as early warning indicators. Detecting adverse effects in flamingo populations can signal the presence of pollutants in the aquatic ecosystem before human health or other species are significantly impacted.
2. Ecosystem Health: Monitoring flamingo populations provides insights into the overall health of aquatic ecosystems. As top consumers in food chains, their status reflects the availability of prey organisms and the quality of their habitats.
3. Public Awareness: Flamingoes are charismatic and well-recognized species, making them effective tools for raising public awareness about water pollution. Their plight can stimulate interest in conservation efforts and pollution reduction.
Sensitivity to Pollution
Several studies have shown that flamingoes exhibit sensitivity to water pollution through various physiological and behavioral responses. For example, changes in foraging patterns, reduced reproductive success, altered feather coloration, and increased mortality rates have been linked to polluted environments. These changes reflect the impact of contaminants like heavy metals, pesticides, and organic pollutants on flamingo populations.The Use of Flamingoes in Water Pollution StudiesFlamingos have been used in water pollution studies around the world. For example, a study in Mexico found that the number of flamingos in a lake decreased significantly after a nearby factory began to discharge pollutants into the water.Another study in India found that flamingos with pale feathers were more likely to be found in areas with high levels of pollution. This is because the pollutants can damage the pigments in the flamingos' feathers, making them appear paler.Flamingos have also been used to measure the levels of heavy metals in water. For example, a study in Spain found that the concentration of lead in flamingo feathers was correlated with the concentration of lead in the water they were feeding in.
Mechanisms of Sensitivity
Flamingoes' sensitivity to water pollution can be attributed to their feeding behavior, biology, and physiology. Contaminants accumulated through their diet can disrupt metabolic processes, impair reproductive success, and compromise overall health. Additionally, pollutants can accumulate in their tissues over time, leading to long-term negative effects. Flamingoes' filter-feeding mechanism exposes them to a wide range of pollutants present in the water column.
The dilemma
These birds have begun congregating in India’s largest city in astonishing numbers. A count in January this year found 120,000 flamingos in the city – three times their highest population in at least four decades.Of the six species of flamingos in the world, it is the greater flamingo (taller, with a black-tipped pink bill) and the near-threatened lesser flamingo (shorter, with a dark crimson bill) that are found in India. The birds arrive in Mumbai from the north-west, from Kutch in Gujarat and Sambhar Lake in Rajasthan. Smaller numbers of the birds are believed to fly in from Pakistan, Afghanistan, Iran and Israel. Some are thought to come from as far as France.In Mumbai most settle in Thane Creek, home to around 200 species of birds. They can also be spotted on smaller wetlands such as those at NRI colony and TS Chanakya. it is premature to speculate on the cause of the huge spike in the flamingo population; the birds’ polluted habitat appears to hold clues. Thane Creek has become a dumping ground for untreated domestic sewage and industrial effluents from the city – and one of the best sites to spot large flamingo congregations in Mumbai is near the Bhandup water treatment plant.
Flamingos eat plankton in front of an
industrial area at Sewri mudflats, Mumbai.
Eutrophication and algal blooms have sparked worldwide concern because of their widespread effects on water-dependent species. Findings indicate that algal blooms can occur at any time in nutrient-enriched water bodies with calm surface waters if they have temperatures exceeding 20 °C, and can last for some days or weeks, depending on the prevalence of the influencing environmental factors .Furthermore, little attention has been paid to quantifying how these blooms might relate to the presence of lesser flamingos.The lesser flamingo (Phoeniconaias minor) is a water-dependent bird, itinerant and obligate algae filter feeder . It feeds on Arthrospira fusiformis, a blue-green algae species abundant in shallow soda lakes and wetlands . Otherwise, the birds will resort to diatoms when their preferred food falls below a certain threshold . The birds forage in either a standing or swimming position or wading in shallow water or muddy areas .The lesser flamingo is treasured because it is an important bio-indicator of ecosystem health and function. However, due to rapid population decline and significant habitat loss caused by human-induced activities in recent years, the IUCN (2018) classed this species as near threatened. Furthermore, several collective behavioural displays help the species synchronise and reproduce once climate conditions, such as temperature, rainfall, and food availability, are favourable . However, understanding factors influencing the lesser flamingos’ presence and temporal changes in the soda lakes outside the breeding season remain a major conservation challenge for the species.The principal foraging requirement for this species is the blue-green algae A. fusiformis that grow in soda lakes under appropriate water chemistry. However, harmful algal blooms negatively impact A. fusiformis’ performance, quantity, and the flamingo’s filter-feeding style and often can lead to the death of this species . high N and P levels in water bodies can promote algae’s rapid growth, resulting in large surface algal blooms and hostile conditions for water-dependent species such as lesser flamingos. The high amounts of N we found in the lakes, particularly between January and April, might be contributed by the lesser flamingo droppings into the water .
Lesser flamingoes
“It is a well-studied
phenomenon in nature that one species’ waste is food for the other. The sewage in the creek promotes biological growth of blue-green algae, which is food for the flamingo. What one might call perfect levels of pollution: Over the years the industrial discharge dispelled by the industries of the Sewri Bay may have warmed the water. The nitrate and phosphate levels in the creek water are just right for the prolific growth of the algae. Although alarmed by the high levels of pollution in the creek, a pristine habitat would deprive flamingos of food and drive them away. This phenomenon is called edge nature,” “Here, wilderness merges with human impact and some species are able to thrive in it. It’s a double-edged sword.”
People watch flamingos from a boat during the Bombay Natural History Society’s flamingo festival.
The continued dumping of sewage and waste into the creek will eventually drive the flamingos out. The dumping of sewage and construction debris in the creek is causing the expansion of the mudflats and surrounding mangroves. At the moment it’s a great situation for the birds, but this continued expansion will cause the creek to dry up. Then there won’t be any mangroves or mudflats and definitely no flamingos.
Flamingo flock feeding
Conclusion
Flamingoes offer a valuable perspective on water quality and pollution levels in aquatic environments. Their sensitivity to contaminants and their position in food chains make them reliable bioindicators. By studying the effects of pollution on flamingo populations, researchers and policymakers can gain valuable insights into the state of aquatic ecosystems and implement effective conservation strategies.
References
Flamingoes in a lake - www.kenyawildlifetours.com
https://rsis.ramsar.org/
Bibliography
Lihepanyama DL, Ndakidemi PA, Treydte AC. Spatio–Temporal Water Quality Determines Algal Bloom Occurrence and Possibly Lesser Flamingo (Phoeniconaias minor) Presence in Momella Lakes, Tanzania. Water. 2022; 14(21):3532. https://doi.org/10.3390/w14213532
Amat, Juan & Green, Andy. (2010). Waterbirds as Bioindicators of Environmental Conditions. 10.1007/978-1-4020-9278-7_5.
Burger, J. (2006). Bioindicators: Types, development, and use in ecological assessment and research. Environmental Bioindicators, 1(1), 22-39.
Burger, J., & Eichhorst, B. (2005). Heavy metals and selenium in grebe eggs from Agassiz National Wildlife Refuge in northern Minnesota. Environmental Monitoring and Assessment, 107(1-3), 285-295.
Amat, J. A., Hortas, F., Arroyo, G. M., Rendón, M. A., Ramírez, J. M., Rendón-Martos, M.,& Garrido, A. (2007). Interannual variations in feeding frequencies and food quality of greater flamingo chicks (Phoenicopterus roseus): Evidence from plasma chemistry and effects on body condition. Comparative Biochemistry and Physiology A, 147(4), 569-576.
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