scholarly journals A survey of fishes of Hombolo Lake, Dodoma, Tanzania, with evidence for local extinction of a native tilapia as a consequence of stocking

2018 ◽  
Author(s):  
George F. Turner ◽  
Benjamin P. Ngatunga ◽  
Martin J Genner

SummaryThe fish community of the Hombolo Lake, an impoundment on the Wami catchment near Dodoma, Tanzania, was surveyed in 2014 and 2017. The lake contains a relatively low diversity community dominated by two Oreochromis species introduced from outside the Wami catchment, O. niloticus and O. esculentus. Evidence from historical collections suggests that the native O. urolepis was formerly present, and its current absence is likely to be the result of competitive exclusion or genetic swamping by non-native species introduced for fishery enhancement. Four other fish species were also recorded.

2019 ◽  
Vol 25 (2) ◽  
pp. 117
Author(s):  
Dimas Angga Hedianto ◽  
Agus Arifin Sentosa

Interaksi trofik pasca masuknya ikan introduksi ataupun ikan asing invasif merupakan dasar untuk mengkaji tekanan ekologis terhadap ikan asli. Penelitian ini bertujuan untuk menganalisis interaksi trofik komunitas ikan pasca berkembangnya jenis-jenis ikan asing invasif di Danau Matano, Sulawesi Selatan. Ikan contoh diperoleh dari hasil tangkapan jaring insang percobaan, jala lempar, dan seser pada Mei, Oktober, dan November 2015 serta Februari, Juli, dan September 2016. Analisis ekologi trofik yang dilakukan meliputi indeks bagian terbesar, tingkat trofik, luas relung dan tumpang tindih relung makanan, serta pola strategi makan. Hasil penelitian menunjukkan komunitas ikan yang tertangkap di Danau Matano terdiri atas 9 famili, 11 genera, dan 17 spesies. Ikan louhan mendominasi komunitas ikan di Danau Matano sebesar 53,62%. Makanan alami yang banyak dimanfaatkan oleh sejumlah ikan dalam komunitas adalah insekta (Diptera), Gastropoda (Tylomelania sp.), dan larva insekta (Chironomidae). Kelompok trofik komunitas ikan di Danau Matano terdiri atas detritivora, herbivora, insektivora, zoobentivora, dan piscivora. Masuknya ikan introduksi memunculkan kelompok trofik baru (detritivora dan herbivora). Ikan introduksi cenderung memiliki luas relung makanan yang lebih bervariasi. Kompetisi terhadap makanan alami kategori moderat banyak terjadi antara ikan asli dengan louhan. Strategi pola makan ikan asli di Danau Matano cenderung bersifat spesialis, sedangkan ikan introduksi memiliki strategi pola makan yang lebih bervariasi dan oportunistik. Ikan louhan sebagai ikan introduksi dominan yang bersifat invasif mampu memanfaatkan seluruh sumber daya makanan alami yang tersedia dan menempati tingkat trofik tertinggi di Danau Matano. Tekanan ekologi terhadap ikan asli oleh ikan asing invasif di Danau Matano terjadi karena adanya kompetisi terhadap makanan alami.Trophic interactions post-develpment of non-native fish or invasive alien fish species are the basis knowledge for assessing and preventing the ecological pressure on native fish. This research aims to analyze the trophic interactions of fish community post-development of invasive alien fish species in Lake Matano, South Sulawesi. Fish samples were obtained from the catch of experimental gill nets, cast nets, and push nets in May, October, and November 2015 along with February, July, and September 2016. Trophic ecological analysis carried out included index of preponderance, trophic level, niche breadth and niche overlap of natural food, and feeding strategy. The fish community caught in Lake Matano consists of 9 families, 11 genera, and 17 species. Flowerhorn cichlid dominates the fish community in Lake Matano by 53.62%. Natural foods that are widely used by a number of fish in the community are Insecta (Diptera), Gastropods (Tylomelania sp.), and larvae of Insecta (Chironomidae). The guild trophic of fish community in Lake Matano consists of detritivores, herbivores, insectivores, zoobentivores, and piscivores. The introduction of non-native species bring up to new guilds (detritivores and herbivores). Non-native fishes tends to have a variety niche breadth. Moderate competition for natural food resources between native fish and flowerhorn cichlid is quite high. Feeding strategy of native species in Lake Matano tend to be specialist, while non-natives species have more variety and opportunistic. Flowerhorn cichlid as dominant invasive alien fish species is able to utilize all natural food resources and occupies the highest trophic level in Lake Matano. Ecological pressure on native fish by invasive alien fish species in Lake Matano occurs due to competition in obtaining natural food resources.


2021 ◽  
Vol 22 (10) ◽  
Author(s):  
MUJIYANTO MUJIYANTO ◽  
YAYUK SUGIANTI ◽  
YUSUF ARIEF AFANDY ◽  
RISNAWATI RAHAYU ◽  
R. ARIEF BUDIKUSUMA ◽  
...  

Abstract. Mujiyanto, Sugianti Y, Afandy YA, Rahayu R, Bidikusuma RA, Nasriri AS, Syam AR, Purnaningtyas SE. 2021. Reef fish community structure in the islands of Paraja Bay, Pandeglang District, Banten, Indonesia. Biodiversitas 22: 4402-4413. Paraja Bay waters have five small islands that coexist with Ujung Kulon National Marine Park and act as a buffer zone for the diversity of fishery resources. This study aimed to assess the reef fishes community structure at small islands in Paraja Bay. Observations were made in 20 locations during August and September 2019 in the five small islands. Reef fishes community structure showed 106 species as included major group (54 species), indicator group (24 species) and target group (28 species), among five small islands, i.e. Badul, Mangir, Oar, Sumur and Umang Islands. The highest reef fishes abundance was founded in Umang Island waters. Several target fish species recorded during the study were mature fish (such as those targeted by fishermen). Only a small proportion were juveniles. Reef fish community structure was categorized as stress community to stable community with its indication was low diversity value, high evenness index, and low dominance. The low diversity index value illustrates that the level of uniformity of reef fish species in Paraja Bay waters is high. This condition is evidenced by each coral fish group's evenness index included in the main species group around 0.93 to 0.98. The target species is 0.88 to 0.99.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Łukasz Głowacki ◽  
Andrzej Kruk ◽  
Tadeusz Penczak

AbstractThe knowledge of biotic and abiotic drivers that put non-native invasive fishes at a disadvantage to native ones is necessary for suppressing invasions, but the knowledge is scarce, particularly when abiotic changes are fast. In this study, we increased this knowledge by an analysis of the biomass of most harmful Prussian carp Carassius gibelio in a river reviving from biological degradation. The species' invasion followed by the invasion's reversal occurred over only two decades and were documented by frequent monitoring of fish biomass and water quality. An initial moderate improvement in water quality was an environmental filter that enabled Prussian carp’s invasion but prevented the expansion of other species. A later substantial improvement stimulated native species’ colonization of the river, and made one rheophil, ide Leuciscus idus, a significant Prussian carp’s replacer. The redundancy analysis (RDA) of the dependence of changes in the biomass of fish species on water quality factors indicated that Prussian carp and ide responded in a significantly opposite way to changes in water quality in the river over the study period. However, the dependence of Prussian carp biomass on ide biomass, as indicated by regression analysis and analysis of species traits, suggests that the ecomorphological similarity of both species might have produced interference competition that contributed to Prussian carp’s decline.


2003 ◽  
Vol 60 (12) ◽  
pp. 1552-1574 ◽  
Author(s):  
Charles R Bronte ◽  
Mark P Ebener ◽  
Donald R Schreiner ◽  
David S DeVault ◽  
Michael M Petzold ◽  
...  

Changes in Lake Superior's fish community are reviewed from 1970 to 2000. Lake trout (Salvelinus namaycush) and lake whitefish (Coregonus clupeaformis) stocks have increased substantially and may be approaching ancestral states. Lake herring (Coregonus artedi) have also recovered, but under sporadic recruitment. Contaminant levels have declined and are in equilibrium with inputs, but toxaphene levels are higher than in all other Great Lakes. Sea lamprey (Petromyzon marinus) control, harvest limits, and stocking fostered recoveries of lake trout and allowed establishment of small nonnative salmonine populations. Natural reproduction supports most salmonine populations, therefore further stocking is not required. Nonnative salmonines will likely remain minor components of the fish community. Forage biomass has shifted from exotic rainbow smelt (Osmerus mordax) to native species, and high predation may prevent their recovery. Introductions of exotics have increased and threaten the recovering fish community. Agencies have little influence on the abundance of forage fish or the major predator, siscowet lake trout, and must now focus on habitat protection and enhancement in nearshore areas and prevent additional species introductions to further restoration. Persistence of Lake Superior's native deepwater species is in contrast to other Great Lakes where restoration will be difficult in the absence of these ecologically important fishes.


2007 ◽  
Vol 67 (3) ◽  
pp. 433-445 ◽  
Author(s):  
ML. Petesse ◽  
M. Petrere Jr. ◽  
RJ. Spigolon

The temporal succession of fish communities allows evaluating the environmental conditions and the adaptation capacity of the fish species to anthropogenic stress in reservoirs. The fish community at Barra Bonita reservoir was sampled in two different periods of the year (dry and rainy) and in three different areas of the reservoir (fluvial, transition, and lentic). The species list was compared to another four lists, trying to detect the transformations of the fish community for the last 15 years. In order to evaluate the adaptation of the present fish community to the hydraulic management of reservoir, the trophic and reproductive structures were studied. Temporal succession analysis shows little change in fish richness of the communities. The number of fish species varies between 23 and 39 for a total of 68 registered species. From this, 27 can be considered constant, 14 accessory and 27 accidental; the main differences observed were for Anostomidae, Loricariidae and Characidae families. In relation to the hydraulic management, we found a fish community stabilized and adapted to environmental stress. This is characterized by the dominance of small-sized fish species of opportunistic diet and high reproductive compensation (r-strategists). The overlap of biological cycles of the most abundant species with the reservoir level fluctuations points to the period from September to March-April as critical for reproductive success and only the species with partial reproductive strategy or parental care are best succeeded. These results, interpreted in the context of the reservoir aging process, indicate that Barra Bonita reservoir is entering a transition phase, between the colonization and aging stages.


2008 ◽  
Vol 6 (2) ◽  
pp. 275-281 ◽  
Author(s):  
Luciano de Oliveira Garcia ◽  
Carlos Eduardo Copatti ◽  
Flávio Wachholz ◽  
Waterloo Pereira Filho ◽  
Bernardo Baldisserotto

In this study we verified data of water temperatures collected by CORSAN-RS from 1996 to 2004 in several cities of the state of Rio Grande do Sul, southern Brazil, and analyzed the possibility of raising the most cultivated fish species in Brazil. The water temperature from 1996 to 2004 was 16 to 28ºC in summer, 17 to 23ºC in fall, 14 to 17ºC (down to 9ºC in the coldest months) in winter and 14 to 21ºC in spring. Native species of this state, such as silver catfish (Rhamdia quelen), traíra (Hoplias malabaricus), dorado (Salminus brasiliensis), pintado (Pimelodus maculatus), as well as carps (family Cyprinidae), are resistant to the low winter temperatures. These species have a lower growth rate in coldest months (winter/spring) but a good development in warmer months (summer/fall), reaching a satisfactory performance throughout the year. In the periods of more intense cold, mortality of some introduced species, such as surubim from Amazon Basin (Pseudoplatystoma sp.), pirapitinga (Piaractus brachypomus), pirarucu (Arapaimas gigas), pacu (Piaractus mesopotamicus), tambaqui (Colossoma macropomum) and Nile tilapia (Oreochromis niloticus) may occur. In addition, as most tropical species have a thermal range for growth and reproduction between 20 to 28ºC, some species may have poor development even in fall. Therefore, water temperature in this state should be considered in the choice of fish species to be cultivated.


Author(s):  
Tatia Kuljanishvili ◽  
Levan Mumladze ◽  
Bella Japoshvili ◽  
Namig Mustafayev ◽  
Shaig Ibrahimov ◽  
...  

The South Caucasus (SC) region is recognized for its high biological diversity and various endemic animal taxa. The area has experienced many fish introductions over the years, but the overall information about non-native fishes in the three SC countries, Armenia, Azerbaijan, and Georgia did not exist. Although these three countries belong to the Kura River drainage, Caspian Sea basin (only the western half of Georgia drains into the Black Sea), the legislative framework for each country regarding introduction of non-native fish species and their treatment is different and poorly developed. The goal of the present study was to make an initial inventory of non-native fish species in the three SC countries, and summarize the existing knowledge as a basis for future risk assessment models and formulation of regional management policies. Here, we present a unified list of 27 non-native species recorded in the wild in Armenia, Azerbaijan, and Georgia. Among these 27 species, eight were translocated from the Black Sea basin to the Caspian Sea basin. Out of these 27 non-native fishes, 15 species have become established (three of them being considered invasive) and six fish species could not survive in the wild.


2006 ◽  
Vol 4 (4) ◽  
pp. 427-433 ◽  
Author(s):  
Paulo dos Santos Pompeu ◽  
Hugo Pereira Godinho

In the Neotropics, a large proportion of fish communities of large rivers use floodplain as habitats for feeding, reproduction, and refuge. An evaluation was made of the effects of extended dry periods on the species richness, abundance and local extinction of fish species in three marginal lagoons in the middle São Francisco River, southeastern Brazil. The studied lagoons fail to receive river floods during the study period (1994-1996). A gradual reduction in richness and abundance was observed in all lagoons. Migratory fish species had the highest probability to become extinct in the two lagoons that remained with large water volume. Species tolerant to low levels of dissolved oxygen had the lowest probability of local extinction in the lagoon showing an abrupt reduction in water volume. Similar changes to those observed in the current study are likely to occur in the floodplains if dams would be constructed in this segment of the river. Adequate water releases from Três Marias reservoir, located upstream, should be considered as a management tool for producing episodic flooding on the marginal lagoons of the region.


1983 ◽  
Vol 61 (11) ◽  
pp. 2446-2464 ◽  
Author(s):  
Lawrence C. Halyk ◽  
Eugene K. Balon

Fish species richness in floodplain pools results from species addition by spring invasion from the stream and species subtraction by local extinction throughout the summer. Local extinction is the more important of the two components. Nineteen floodplain pools (1 to 597 m2) and an adjacent section of Irvine Creek (43°44′ N, 80°25′ W), Ontario, Canada, were treated with a piscicide to test if the pools contribute significantly to the resource potential of the river basin. Altogether, 41 626 fishes of 20 species were collected. Number of days of stream connection in the spring was not significantly correlated with fish species richness in the pools (P < 0.10). A significant correlation (P < 0.05, r = 0.7413) was found between species richness and the logarithm of pool area. The total fish production for the Irvine Creek section, adjusted to account for dominant and nondominant species, was 298 kg∙ha−∙year−1. Production for this site was underestimated by 49% when weights and densities were backcalculated to time of annulus formation. Total production estimates of the floodplain pools ranged from 135 to 314 kg∙ha−1∙year−1. Stream connection duration affects pool fish production by regulating accessibility to the young of stream spawning species. Floodplain pools are beneficial to the Irvine Creek system. As nursery areas, floodplain pools produce fish biomass which can return to the stream during periods of stream–pool connection. These pools may also act as fish havens if catastrophic stream mortality occurs.


1991 ◽  
Vol 48 (S1) ◽  
pp. 167-170 ◽  
Author(s):  
Paul J. Wingate

A survey of the poiicy of 50 U.S. states on transplanted fish introductions and stocking fish of different genetic strains indicates that all 39 responding states control exotic introductions. While 67% of the responding states restrict in-state movement of fish species, more attention is being given to restricting in-state strain movement. More needs to be done. Native species are stocked on top of reproducing populations and moved among watersheds; exotic species are introduced. In some cases, these stockings have appeared to benefit all interested parties, while in other circumstances exotics have totally disrupted ecosystems and become pests. These introductions and stockings are a combination of the fish being available, misunderstanding by managers of possible effects, and strong political pressure to satisfy anglers in more and more waters. Many times, little attention is given to the effect of these introductions on the native biota and fauna as it is perceived that stocking fish is a good thing. It is not until problems develop or anglers want another species added that the wisdom or success of these stockings is questioned. Minnesota's policy is that fish are not moved between watersheds until genetic similarities of the various species in the different watersheds are demonstrated.


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