Norte Chico civilization Cotton and food sources Are there any other interesting aspects about this article? Cotton (of the species Gossypium barbadense) likely provided the basis of the dominance of inland over coast (whether development was earlier, later, or contemporaneous). What was their civilization like? Norte Chico's development is particularly remarkable for the apparent absence of a staple food. Why is it remarkable? Though not edible, it was the most important product of irrigation in the Norte Chico, vital to the production of fishing nets (that in turn provided maritime resources)
What food sources did they have the most abundance of?
What food sources did Norte Chico have the most abundance of?
Cotton (of the species Gossypium barbadense) likely provided the basis of the dominance of inland over coast (whether development was earlier, later, or contemporaneous). Though not edible, it was the most important product of irrigation in the Norte Chico, vital to the production of fishing nets (that in turn provided maritime resources) as well as to textiles and textile technology. Haas notes that "control over cotton allows a ruling elite to provide the benefit of cloth for clothing, bags, wraps, and adornment". He is willing to admit to a mutual dependency dilemma: "The prehistoric residents of the Norte Chico needed the fish resources for their protein and the fishermen needed the cotton to make the nets to catch the fish." Thus, identifying cotton as a vital resource produced in the inland does not by itself resolve the issue of whether the inland centers were a progenitor for the coast, or vice versa. Moseley argues that successful maritime centers would have moved inland to find cotton. The exact relationship between food resources and political organization remains unresolved. Norte Chico's development is particularly remarkable for the apparent absence of a staple food. However, recent studies increasingly dispute this and point to maize as a dietary backbone of this and later pre-Columbian civilizations. Moseley found a small number of maize cobs in 1973 at Aspero (also seen in site work in the 1940s and 50s) but has since called the find "problematic". However, increasing evidence has emerged about the importance of maize in this period: Archaeological testing at a number of sites in the Norte Chico region of the north central coast provides a broad range of empirical data on the production, processing, and consumption of maize. New data drawn from coprolites, pollen records, and stone tool residues, combined with 126 radiocarbon dates, demonstrate that maize was widely grown, intensively processed, and constituted a primary component of the diet throughout the period from 3000 to 1800 B.C. CANNOTANSWER
fish.
Norte Chico (also known as Caral or Caral-Supe) was a complex pre-Columbian-era society that included as many as thirty major population centers in what is now the Caral region of north-central coastal Peru. The civilization flourished between the fourth and second millennia BC, with the formation of the first city generally dated to around 3500 BC, at Huaricanga, in the Fortaleza area. It is from 3100 BC onward that large-scale human settlement and communal construction become clearly apparent, which lasted until a period of decline around 1800 BC. Since the early twenty-first century, it has been established as the oldest-known civilization in the Americas.

This civilization flourished along three rivers, the Fortaleza, the Pativilca, and the Supe. These river valleys each have large clusters of sites. Farther south, there are several associated sites along the Huaura River. The alternative name, Caral-Supe, is derived from the city of Caral in the Supe Valley, a large and well-studied Caral-Supe site. 

Complex society in Caral-Supe arose a millennium after Sumer in Mesopotamia, was contemporaneous with the Egyptian pyramids, and predated the Mesoamerican Olmec by nearly two millennia.

In archaeological nomenclature, Caral-Supe is a pre-ceramic culture of the pre-Columbian Late Archaic; it completely lacked ceramics and apparently had almost no visual art. The most impressive achievement of the civilization was its monumental architecture, including large earthwork platform mounds and sunken circular plazas. Archaeological evidence suggests use of textile technology and, possibly, the worship of common deity symbols, both of which recur in pre-Columbian Andean cultures. Sophisticated government is presumed to have been required to manage the ancient Caral. Questions remain over its organization, particularly the influence of food resources on politics.

Archaeologists have been aware of ancient sites in the area since at least the 1940s; early work occurred at Aspero on the coast, a site identified as early as 1905, and later at Caral, farther inland. In the late 1990s, Peruvian archaeologists, led by Ruth Shady, provided the first extensive documentation of the civilization with work at Caral. A 2001 paper in Science, providing a survey of the Caral research, and a 2004 article in Nature, describing fieldwork and radiocarbon dating across a wider area, revealed Caral-Supe's full significance and led to widespread interest.

History and geography

The dating of the Caral-Supe sites has pushed back the estimated beginning date of complex societies in the Peruvian region by more than one thousand years. The Chavín culture, circa 900 BC, had previously been considered the first civilization of the area. Regularly, it still is cited incorrectly as such in general works.

The discovery of Caral-Supe also has shifted the focus of research away from the highland areas of the Andes and lowlands adjacent to the mountains (where the Chavín, and later Inca, had their major centers) to the Peruvian littoral, or coastal regions. Caral is located in a north-central area of the coast, approximately 150 to 200 km north of Lima, roughly bounded by the Lurín Valley on the south and the Casma Valley on the north. It comprises four coastal valleys: the Huaura, Supe, Pativilca, and Fortaleza. Known sites are concentrated in the latter three, which share a common coastal plain. The three principal valleys cover only 1,800 km², and research has emphasized the density of the population centers.

The Peruvian littoral appears an "improbable, even aberrant" candidate for the "pristine" development of civilization, compared to other world centers. It is extremely arid, bounded by two rain shadows (caused by the Andes to the east, and the Pacific trade winds to the west). The region is punctuated by more than 50 rivers that carry Andean snowmelt. The development of widespread irrigation from these water sources is seen as decisive in the emergence of Caral-Supe; since all of the monumental architecture at various sites has been found close to irrigation channels.

The radiocarbon work of Jonathan Haas et al., found that 10 of 95 samples taken in the Pativilca and Fortaleza areas dated from before 3500 BC. The oldest, dating from 9210 BC, provides "limited indication" of human settlement during the Pre-Columbian Early Archaic era. Two dates of 3700 BC are associated with communal architecture, but are likely to be anomalous. It is from 3200 BC onward that large-scale human settlement and communal construction are clearly apparent. Mann, in a survey of the literature in 2005, suggests "sometime before 3200 BC, and possibly before 3500 BC" as the beginning date of the Caral-Supe formative period. He notes that the earliest date securely associated with a city is 3500 BC, at Huaricanga, in the Fortaleza area of the north, based on Haas's dates.

Haas's early-third-millennium dates suggest that the development of coastal and inland sites occurred in parallel. But, from 2500 to 2000 BC, during the period of greatest expansion, the population and development decisively shifted toward the inland sites. All development apparently occurred at large interior sites such as Caral, although they remained dependent on fish and shellfish from the coast. The peak in dates is in keeping with Shady's dates at Caral, which show habitation from 2627 BC to 2020 BC. That coastal and inland sites developed in tandem remains disputed, however (see next section).

Circa 1800 BC, the Caral-Supe civilization began to decline, with more powerful centers appearing to the south and north along the coast, and to the east inside the belt of the Andes. The success of irrigation-based agriculture at Caral-Supe may have contributed to its being eclipsed. Anthropologist Professor Winifred Creamer of Northern Illinois University notes that "when this civilization is in decline, we begin to find extensive canals farther north. People were moving to more fertile ground and taking their knowledge of irrigation with them". It would be a thousand years before the rise of the next great Peruvian culture, the Chavín.

Geographical links 
Cultural links with the highland areas have been noted by archaeologists. In particular, the links with the Kotosh Religious Tradition have been suggested.

Numerous architectural features found among the settlements of Supe, including subterranean circular courts, stepped pyramids and sequential platforms, as well as material remains and their cultural implications, excavated at Aspero and the valley sites we are digging (Caral, Chupacigarro, Lurihuasi, Miraya), are shared with other settlements of the area that participated in what is known as the Kotosh Religious Tradition.Lucy Salazar-Burger, 1985, The early ceremonial center of Huaricoto. In Early Ceremonial Architecture in the Andes, edited by Christopher B. Donnan, pp. 111–138. Dumbarton Oaks Research Library and Collection, Washington, D.C. Most specific among these features include rooms with benches and hearths with subterranean ventilation ducts, wall niches, biconvex beads, and musical flutes.

Maritime coast and agricultural interior 
Research into Caral-Supe continues, with many unsettled questions. Debate is ongoing regarding two related questions: the degree to which the flourishing of the Caral-Supe was based on maritime food resources, and the exact relationship this implies between the coastal and inland sites.

Confirmed diet 
A broad outline of the Caral-Supe diet has been suggested. At Caral, the edible domesticated plants noted by Shady are squash, beans, lúcuma, guava, pacay (Inga feuilleei), and sweet potato. Haas et al. noted the same foods in their survey farther north, while adding avocado and achira. In 2013, good evidence for maize also was documented by Haas et al. (see below).

There was also a significant seafood component at both coastal and inland sites. Shady notes that "animal remains are almost exclusively marine" at Caral, including clams and mussels, and large amounts of anchovies and sardines. That the anchovy fish reached inland is clear, although Haas suggests that "shellfish [which would include clams and mussels], sea mammals, and seaweed do not appear to have been significant portions of the diet in the inland, non-maritime sites".

Theory of a maritime foundation for Andean civilization 

The role of seafood in the Caral-Supe diet has aroused debate. Much early fieldwork was conducted in the region of Aspero on the coast, before the full scope and inter-connectedness of the several sites of the civilization were realized. In a 1973 paper, Michael E. Moseley contended that a maritime subsistence (seafood) economy had been the basis of the society and its remarkably early flourishing, a theory later elaborated as a "maritime foundation of Andean civilization" (MFAC). He confirmed a previously observed lack of ceramics at Aspero, and he deduced that "hummocks" on the site constituted the remains of artificial platform mounds.

This thesis of a maritime foundation was contrary to the general scholarly consensus that the rise of civilization was based on intensive agriculture, particularly of at least one cereal. The production of agricultural surpluses had long been seen as essential in promoting population density and the emergence of complex society. Moseley's ideas would be debated and challenged (that maritime remains and their caloric contribution were overestimated, for example), but have been treated as plausible as late as 2005, when Mann conducted a summary of the literature.

Concomitant to the maritime subsistence hypothesis was an implied dominance of sites immediately adjacent to the coast over other centers. This idea was shaken by the realization of the magnitude of Caral, an inland site. Supplemental to a 1997 article by Shady dating Caral, a 2001 Science news article emphasized the dominance of agriculture and also suggested that Caral was the oldest urban center in Peru (and the entire Americas). It rejected the idea that civilization might have begun adjacent to the coast and then moved inland. One archaeologist was quoted as suggesting that "rather than coastal antecedents to monumental inland sites, what we have now are coastal satellite villages to monumental inland sites".

These assertions were quickly challenged by Sandweiss and Moseley, who observed that Caral, although being the largest and most complex preceramic site, it is not the oldest. They admitted the importance of agriculture to industry and to augment diet, while broadly affirming "the formative role of marine resources in early Andean civilization". Scholars now agree that the inland sites did have significantly greater populations, and that there were "so many more people along the four rivers than on the shore that they had to have been dominant".

The remaining question is which of the areas developed first and created a template for subsequent development. Haas rejects suggestions that maritime development at sites immediately adjacent to the coast was initial, pointing to contemporaneous development based on his dating. Moseley remains convinced that coastal Aspero is the oldest site, and that its maritime subsistence served as a basis for the civilization.

Cotton and food sources 
It is likely that cotton (of the species Gossypium barbadense) provided the basis of the dominance of inland over coastal (whether development was earlier, later, or contemporaneous). Although not edible, cotton was the most important product of irrigation in the Caral-Supe culture, vital to the production of fishing nets (that in turn provided maritime resources) as well as to textiles and textile technology. Haas notes that "control over cotton allows a ruling elite to provide the benefit of cloth for clothing, bags, wraps, and adornment". He is willing to admit to a mutual dependency dilemma: "The prehistoric residents of the Norte Chico needed the fish resources for their protein and the fishermen needed the cotton to make the nets to catch the fish." Thus, identifying cotton as a vital resource produced in the inland does not by itself resolve the issue of whether the inland centers were a progenitor for those on the coast, or vice versa. Moseley argues that successful maritime centers would have moved inland to find cotton. The exact relationship between food resources and political organization remains unresolved.

The development of Caral-Supe is particularly remarkable for the apparent absence of an agricultural staple food. However, recent studies increasingly dispute this and point to maize as a dietary backbone of this and later pre-Columbian civilizations. Moseley found a small number of maize cobs in 1973 at Aspero (also seen in site work in the 1940s and 1950s) but has since called the find "problematic". However, increasing evidence has emerged about the importance of maize in this period:

Social organization

Government 

The degree of centralized authority is difficult to ascertain, but architectural construction patterns are indicative, at least in certain places at certain times, of an elite population who wielded considerable power: while some of the monumental architecture was constructed incrementally, other buildings, such as the two main platform mounds at Caral, appear to have been constructed in one or two intense construction phases. As further evidence of centralized control, Haas points to remains of large stone warehouses found at Upaca, on the Pativilca, as emblematic of authorities able to control vital resources such as cotton.

Haas suggests that the labour mobilization patterns revealed by the archaeological evidence, point to a unique emergence of human government, one of two alongside Sumer (or three, if Mesoamerica is included as a separate case). While in other cases, the idea of government would have been borrowed or copied, in this small group, government was invented. Other archaeologists have rejected such claims as hyperbolic.

In exploring the basis of possible government, Haas suggests three broad bases of power for early complex societies:
 economic,
 ideology, and
 physical.
He finds the first two present in ancient Caral-Supe.

Economic 
Economic authority would have rested on the control of cotton, edible plants, and associated trade relationships, with power centered on the inland sites. Haas tentatively suggests that the scope of this economic power base may have extended widely: there are only two confirmed shore sites in the Caral-Supe (Aspero and Bandurria) and possibly two more, but cotton fishing nets and domesticated plants have been found up and down the Peruvian coast. It is possible that the major inland centers of Caral-Supe, were at the center of a broad regional trade network centered on these resources.

Citing Shady, a 2005 article in Discover magazine suggests a rich and varied trade life: "[Caral] exported its own products and those of Aspero to distant communities in exchange for exotic imports: Spondylus shells from the coast of Ecuador, rich dyes from the Andean highlands, hallucinogenic snuff from the Amazon." (Given the still limited extent of Caral-Supe research, such claims should be treated circumspectly.) Other reports on Shady's work indicate Caral traded with communities in the jungle farther inland and, possibly, with people from the mountains.

Ideology 
Haas postulates that ideological power exercised by leadership was based on apparent access to deities and the supernatural. Evidence regarding Caral-Supe religion is limited: in 2003, an image of the Staff God, a leering figure with a hood and fangs, was found on a gourd that dated to 2250 BC. The Staff God is a major deity of later Andean cultures, and Winifred Creamer suggests the find points to worship of common symbols of deities. As with much other research at Caral-Supe, the nature and significance of the find has been disputed by other researchers.

Mann postulates that the act of architectural construction and maintenance at Caral-Supe may have been a spiritual or religious experience: a process of communal exaltation and ceremony. Shady has called Caral "the sacred city" (la ciudad sagrada) and reports that socio-economic and political focus was on the temples, which were periodically remodeled, with major burnt offerings associated with the remodeling.

Physical 
Haas notes the absence of any suggestion of physical bases of power, that is, defensive construction, at Caral-Supe. There is no evidence of warfare "of any kind or at any level during the Preceramic Period". Mutilated bodies, burned buildings, and other tell-tale signs of violence are absent and settlement patterns are completely non-defensive. The evidence of the development of complex government in the absence of warfare contrasts markedly to archaeological theory, which suggests that human beings move away from kin-based groups to larger units resembling "states" for mutual defense of often scarce resources. In Caral-Supe, a vital resource was present: arable land generally, and the cotton crop specifically, but Mann noted that apparently, the move to greater complexity by the culture was not driven by the need for defense or warfare.

Sites and architecture 

Caral-Supe sites are known for their density of large sites with immense architecture. Haas argues that the density of sites in such a small area is globally unique for a nascent civilization. During the third millennium BC, Caral-Supe may have been the most densely populated area of the world (excepting, possibly, Northern China). The Supe, Pativilca, Fortaleza, and Huaura River valleys of Caral-Supe each have several related sites.

Evidence from the ground-breaking work during 1973 at Aspero, at the mouth of the Supe Valley, suggested a site of approximately . Surveying of the midden suggested extensive prehistoric construction activity. Small-scale terracing was noted, along with more sophisticated platform mound masonry. As many as eleven artificial mounds were estimated to exist at the site. Moseley calls these "Corporate Labor Platforms", given that their size, layout, and construction materials and techniques would have required an organized workforce.

The survey of the northern rivers found sites between ; between one and seven large platform mounds—rectangular, terraced pyramids—were discovered, ranging in size from  to more than . Shady notes that the central zone of Caral, with monumental architecture, covers an area of just greater than . Also, six platform mounds, numerous smaller mounds, two sunken circular plazas, and a variety of residential architecture were discovered at this site.

The monumental architecture was constructed with quarried stone and river cobbles. Using reed "shicra-bags", some of which have been preserved, laborers would have hauled the material to sites by hand. Roger Atwood of Archaeology magazine describes the process:

Armies of workers would gather a long, durable grass known as shicra in the highlands above the city, tie the grass strands into loosely meshed bags, fill the bags with boulders, and then pack the trenches behind each successive retaining wall of the step pyramids with the stone-filled bags.

In this way, the people of Norte Chico achieved formidable architectural success. The largest of the platforms mounds at Caral, the Piramide Mayor, measures  and rises  high. In its summation of the 2001 Shady paper, the BBC suggests workers would have been "paid or compelled" to work on centralized projects of this sort, with dried anchovies possibly serving as a form of currency. Mann points to "ideology, charisma, and skilfully timed reinforcement" from leaders.

Development and absent technologies 

When compared to the common Eurasian models of the development of civilization, Caral-Supe's differences are striking. In Caral-Supe, a total lack of ceramics persists across the period. Crops were cooked by roasting. The lack of pottery was accompanied by a lack of archaeologically apparent art. In conversation with Mann, Alvaro Ruiz observes: "In the Norte Chico we see almost no visual arts. No sculpture, no carving or bas-relief, almost no painting or drawing—the interiors are completely bare. What we do see are these huge mounds—and textiles."

While the absence of ceramics appears anomalous, Mann notes that the presence of textiles is intriguing. Quipu (or khipu), string-based recording devices, have been found at Caral, suggesting a writing, or proto-writing, system at Caral-Supe. (The discovery was reported by Mann in Science in 2005, but has not been formally published or described by Shady.) The exact use of quipu in this and later Andean cultures has been widely debated. Originally, it was believed to be a simple mnemonic technique used to record numeric information, such as a count of items bought and sold. Evidence has emerged, however, that the quipu also may have recorded logographic information in the same way writing does. Research has focused on the much larger sample of a few hundred quipu dating to Inca times. The Caral-Supe discovery remains singular and undeciphered.

Other finds at Caral-Supe have proved suggestive. While visual arts appear absent, the people may have played instrumental music: thirty-two flutes, crafted from pelican bone, have been discovered.

The oldest known depiction of the Staff God was found in 2003 on some broken gourd fragments in a burial site in the Pativilca River valley and the gourd was carbon dated to 2250 BCE. While still fragmentary, such archaeological evidence corresponds to the patterns of later Andean civilization and may indicate that Caral-Supe served as a template. Along with the specific finds, Mann highlights 
"the primacy of exchange over a wide area, the penchant for collective, festive civic work projects, [and] the high valuation of textiles and textile technology" within Norte Chico as patterns that would recur later in the Peruvian cradle of civilization."

Research 

The magnitude of the Caral-Supe discovery has generated academic controversy among researchers. The "monumental feud", as described by Archaeology, has included "public insults, a charge of plagiarism, ethics inquiries in both Peru and the United States, and complaints by Peruvian officials to the U.S. government". The lead author of the seminal paper of April 2001  was a Peruvian, Ruth Shady, with co-authors Jonathan Haas and Winifred Creamer, a married United States team; the coauthoring was reportedly suggested by Haas, in the hopes that the involvement of United States researchers would help secure funds for carbon dating as well as future research funding. Later, Shady charged the couple with plagiarism and insufficient attribution, suggesting the pair had received credit for her research, which had begun in 1994.

At issue is credit for the discovery of the civilization, naming it, and developing the theoretical models to explain it. That Shady was describing a civilization is clear in 1997 ("Los albores de la civilización en el Perú"). While locating it on the Supe River, with Caral at its center, she suggested a larger geographic base for the society: 

In 2004, Haas et al. wrote that "Our recent work in the neighboring Pativilca and Fortaleza has revealed that Caral and Aspero were but two of a much larger number of major Late Archaic sites in the Norte Chico", while noting Shady only in footnotes. Attribution of this type is what has angered Shady and her supporters. Shady's position has been hampered by a lack of funding for archaeological research in her native Peru, as well as the media advantages of North American researchers in disputes of this type.

Haas and Creamer were cleared of the plagiarism charge by their institutions. The science advisory council of the Chicago Field Museum of Natural History rebuked Haas for press releases and web pages that gave too little credit to Shady and inflated the American couple's role as discoverers. As of 2005, the dispute remains heated. Scholars have concerns that it could make it more difficult for United States archaeologists to gain permission to work in Peru.

See also 

 Andean preceramic
 Iperú, Peru tourist information
 List of Norte Chico archaeological sites
 Supe Puerto

Notes

References

Further reading

External links 

 Caral-Supe at Google Maps
 Northern Illinois University press kit photos
 Press kit photos and video of Caral

 
4th-millennium BC establishments
2nd-millennium BC disestablishments
Andean civilizations
Andean preceramic
Archaeology of Peru
Indigenous peoples in Peru
Pre-Columbian cultures
Meroplankton are a wide variety of aquatic organisms which have both planktonic and benthic stages in their life cycles. Much of the meroplankton consists of larval stages of larger organism. Meroplankton can be contrasted with holoplankton, which are planktonic organisms that stay in the pelagic zone as plankton throughout their entire life cycle.

After a period of time in the plankton, many meroplankton graduate to the nekton or adopt a benthic (often sessile) lifestyle on the seafloor. The larval stages of benthic invertebrates make up a significant proportion of planktonic communities. The planktonic larval stage is particularly crucial to many benthic invertebrate in order to disperse their young. Depending on the particular species and the environmental conditions, larval or juvenile-stage meroplankton may remain in the pelagic zone for durations ranging from hour to months.

Not all meroplankton are larvae or juvenile stages of larger organisms. Many dinoflagellates are meroplanktonic, undergoing a seasonal cycle of encystment and dormancy in the benthic zone followed by excystment and reproduction in the pelagic zone before returning to the benthic zone once more. There also exist meroplanktonic diatoms; these have a seasonal resting phase below the photic zone and can be found commonly amongst the benthos of lakes and coastal zones.

Spatial distribution

Meroplankton species composition depends on spatial distribution and reproductive habits of adults in a given area. Biotic and abiotic factors such as tidal and lunar cycles and availability of food determine adult spawning schedules, in turn,  determining subsequent meroplankton populations. Behavioural factors, such as predator avoidance are also important. Freshwater inputs play a key role in meroplankton species composition in estuarine environments. Effects of tides contribute greatly to meroplankton species distribution. One study conducted in a Patagonian Fjord found that species composition of the meroplankton community depended on the seasonally varying input levels from the Baker river as well as vertical and horizontal stratification of the water column. Events such as wind driven upwelling and downwelling also affect meroplankton species distribution. Most species are swept in the direction of the flow of water, either off shore during an upwelling or near shore during a downwelling. Some species, such as bivalve larvae, have the ability to maintain their nearshore position during these events.

The distribution of meroplankton is also highly seasonal. Many meroplankton have short residence times in the pelagic zone which follow seasonal reproduction patterns. The timing of meroplankton population rises can be used as a proxy to estimate the timing of seasonal reproduction of the species in question.

Dispersal
Survival rate of Meroplankton is critical to successful development of adult organisms. One factor which often determines meroplankton survival is larval dispersal. Most species within the meroplankton community rely on ocean currents for dispersal. Currents play a key role in delivering larval organisms to specific settlement locations, where they are able to transition and mature into adult forms. Organisms which do not make it to the right settlement site are unlikely to complete their lifecycle.

Food availability
A major factor affecting meroplankton survival is food availability. While some larval or juvenile stage organisms are lecitotrophic, many members of the meroplankton community are heterotrophic. In order to ensure that larvae have sufficient sources of nutrition, many species coordinate larval release with times of algal blooms.  This synchronicity between release of larvae and algal blooms often leads to meroplankton making up the largest percentage of the planktonic community during such reproductive periods. It has been demonstrated that certain species are able to commence spawning as they come into contact with phytoplankton cells. These species store embryos in the mantle cavity until they detect algal blooms. This adaptation allows for better larval survival.

Diversity and abundance
Meroplankton diversity and abundance are affected by many factors. Seasonal and spatial variations are among some of the main causes of such variability. A study which was conducted in Dunkellin Estuary, determined that spawning times of many species are timed to maximise food availability at a particular time of year, while minimising presence of other species which exploit the same food source  Diversity and abundance are depth dependent qualities. Generally, shallow coastal waters contain far greater numbers of meroplankton than deep, open ocean waters. Most abundant regions occur at depths between 0 and 200 meters of the water column, where light penetration is highest. Availability of sunlight allows for proliferation of phytoplankton, which serves as one of the major food sources for meroplankton. Deep oceanic waters show significantly lower abundance than shelf regions, due to poor light penetration.

Effects of pollution 
Water and benthos pollution from industrial sources has been demonstrated to have varying  effects on biological diversity and survival potential of meroplankton. One study conducted in the Vostok Bay region in Russia, demonstrated that even in the presence of industrial pollutants, most species of meroplankton were able to proliferate almost unaffected. The authors of this study attribute these findings to the fact that meroplankton are transported by ocean currents generally from cleaner open waters inshore. Furthermore, the same study also concluded that even in heavily polluted areas, meroplankton populations were able to reestablish if pollution was brought under control and sufficient time was allowed to pass. However, the rate of recolonization was demonstrated to be notably slow, on average talking about 10 years before the abundance and diversity of meroplankton returned to its original levels. This is in part due to the slow nature of detoxification of benthic sediments, which retain much of the heavy metal pollution

Meroplankton and climate change 
A study conducted in the  North Sea between 1958-2005, collected samples of meroplankton using a CPR survey. These samples consisted of larval echinoderms, decapods, bivalves, cirripedes, and ectoprocts. Meroplankton abundance as well as PCI levels (amount of chlorophyll in each sample in relation to sea surface temperature) were examined. Researchers concluded that echinoderm larvae increased in abundance throughout the study, with the largest increase occurring in the Northern and Central regions. Decapod larvae were found to increase in abundance as well, and were found to appear earlier in the year. Bivalve larvae showed an overall decline in abundance. It was also concluded that PCI levels increased throughout the study, particularly during the summer months. It was determined that climate, particularly sea surface temperature, drives meroplankton abundance. Warmer sea surface temperature shortens developmental time of the larvae, increasing their survival rate.

See also 
 Plankton 
 Holoplankton
 Ichthyoplankton
 Zooplankton
 Nekton

References

Sources
 Meroplankton (Australian Museum)

Aquatic ecology
Planktology
Oceanographical terminology Mesograzers are defined as small invertebrate herbivores less than 2.5 cm in length (i.e., 1 inch), and can include juveniles of some larger species. The feeding behaviour of these small invertebrate herbivores is what classifies them as mesograzers. They are commonly found abundantly on Microalgae, seagrass beds, giant kelp, and coral reefs globally, since these are their main food sources and habitats.  Their foraging behaviour is grazing on the organism they are living on, where there are typically masses reaching tens of thousands of mesograzers per meter of habitat. They experience predation from micro-carnivorous fish that help regulate the population of kelp and other common food sources of mesograzers by controlling the population of mesograzers; consequently, grazing is an important process linking aquatic vegetation to higher trophic level. Mesograzers show important top-down effect on marine communities, depending on the diversity and presence of predators. Mesograzers are typically overlooked in scientific research however their foraging effects have been suggested to have extreme effects on the population of their common food sources. They both positively and negatively affect macroalgal performance and productivity through grazing on algal (i.e., negative effect), or through removing epiphytes (i.e., positive effects). Mesograzers typically exist in spaces lacking enemies by inhabiting, therefore consuming, marine vegetation which are defended against more mobile, larger consumers through chemical defenses.

Mesograzers are quite common in the marine environment, common examples of mesograzers are small Gastropoda, Amphipoda, Isopoda, and small Crustaceans.

Diet 

Mesograzers consume a variety of marine vegetation. They typically use the same marine plant as both their habitat and food source. Many mesograzers have been found on sea grass beds. They are also quite known for destroying large populations of giant kelp, as this is another popular source for mesograzers. Other common food sources of mesograzers are coral reefs and macroalgal. They can be found living and feeding on these marine plants worldwide. Mesograzers have even been shown to consume invasive species of microalgae.

Ecological role 
There is little understanding of mesograzers ecological role. Examination of mesograzer outbreaks in natural, as well as aquacultural settings suggests that they have the potential to alter the abundance of algal. However, the rarity of such events infers that the impact of mesograzers is more than likely insignificant. Nonetheless, observations alone are not significant enough to quantify their ecological role. Many researchers have tried to determine community-wide effects of mesograzers in laboratory studies. This has proven to be difficult due to high spatial and temporal variation in the density of mesograzers, variation in feeding behaviour, along with variable relationships between plant fitness and mesograzers consumption rates. These factors make it difficult to replicate a mesograzers natural environment in a laboratory setting. This difficulty lends to the low understanding of mesograzers ecological role in marine communities. The strongest evidence for mesograzers altering a marine community thus far demonstrates the ability of mesograzers to limit populations of algal epiphytes, which in turn shows benefits for sea grass. However, there is a high need for further field research in this area.

In gastropods 

Grazing herbivorous gastropods are known as mesograzers. They are commonly known to graze upon epilithic microalgae on rocky shores. The grazing gastropods in these regions are exposed to daily exposure to air, as well as immersion in seawater, due to the tides. Intertidal grazing gastropods can therefore get their food from epilithic microalgae and planktonic microalgae deposited during the tidal shift. However, they obtain most of their food by grazing on the microalgae on the rock surface. The algae availability along with feeding capability will determine the diets of the gastropod grazers on rocky shores. Different gastropod grazers with varying radula morphology are known to use the same food source. A possible explanation is that the gastropods may find differentiating between the various types of microalgae in their environment quite difficult.

The marine vegetation consumed by grazing gastropods occasionally produces chemical deterrents to prevent mesograzers from feeding on them. Different gastropod grazers elicit different plant responses.

In crustaceans 
Many crustacean species depend largely on animals as their food source, however others feed on pure algal diets (e.g., cyclopoid). Different species of cyclopoid have various mouth parts. This affects if they are grazers or predators, and if grazers, what vegetation they will prefer to graze on. Temperature also has an effect on the grazing behaviour of certain small crustaceans. The relationship between algal and grazer typically shifts with the seasons.

Isopoda

Isopoda are an order of crustacean commonly known as mesograzers, due to their general small size and grazing herbivorous feeding behaviour. The mechanisms affecting their habitat choice and grazing in sea grass meadows is affected by the latitude. For isopod grazers, food type is considered a universal mechanism in determining the presence of these grazers on sea grass meadows. Food is more important than shelter, in the absence of predators, regarding habitat choice. Many factors, such as food quality, location, predation, plant morphology, and physiology of the isopod affect food, thus habitat choice. Isopod grazers typically respond to substances excreted by their food source, particu00larly epiphytes alone do not attract isopods (e.g., snails).

Amphipoda

Amphipoda are an order of crustacean that typically graze on algae, considering them mesograzers. Due to global stressors, the population main food sources for amphipods, such as algae, have seen some fluctuation. To ensure they are feeding on the best algae, amphipods have many strategies to picking algae to graze on. To optimize their diet they choose the most nutritive algae, or they increase their consumption rate and/or absorption efficiency while grazing on less nutrient rich algae. These amphipod mesograzers use their host vegetation as both food and habitat, therefore the extent of their impact on benthic communities is related to patterns of host use by these consumers. Food and shelter have been defined as the main factors determining these amphipods' host.

References

 Marine Ecology Progress Series 207: 227–241, 2000.
 correct citation: Wright J.T., de Nys R., Steinberg P.D. 2000 Geographic-scale patterns of algal chemical defence: the relationship between quantitative variation in secondary metabolites, herbivores and epiphytes. Marine Ecology Progress Series 207, 227-241.

Animals by eating behaviors