Project title :Conservation Ecology of the Nile crocodile and Community Environmental Education to resolve the conflicts between the Nile Crocodiles and Man, in Lake Nasser –EGYPT
The project activities that carried in and out Lake Nasser upon the Nile crocodile described in detail in the project report on the other hand due to the larger size and a lot of format in this report we divided the report into 9 chapters included 3 chapters with two parts We uploaded all of these parts separately as a PDF format as well as word document but in two compressed part in section of Media coverage of this project, so for further detail please try to look up this section and read as you can in that section.But we will try to summarize the project activities according to the following sentences.
First the project inclouded these titles
Chapter 1: A REVIEW OF SCIENTIFIC STUDIES FOCUSING ON CROCODILE CROCODYLUS NILOTICUS) IN AFRICA AND EGYPT…………………………………. Chapter 9: Workshop and Building Capacity for upcoming generations, fishermen, stakeholders and others Held in Aswan and Lake Nasser – Egypt On the behalf of community environmental education program of Nile crocodile………………………….. In Chapter I, the author gives a review upon what was published in articles about the Nile crocodile in Egypt and Africa and he also summarized the Nile crocodile history and evaluation and role in the ecosystem, and now have a look up on part of this chapter A REVIEW OF SCIENTIFIC STUDY FOCUSING ON THE NILE CROCODILENile crocodile (CROCODYLUS NILOTICUS) IN AFRICA and EGYPTNile crocodile history, evaluation and role in the ecosystemFossil relics of primitive crocodilians, of thecodonts ancestry, come out in the Upper Triassic period some 200 million years ago. In this era, the wiped out thecodonts, the dinosaurs, the pterosaurs, or flying reptiles and the ancestors of the birds as reported by (Gatesy et al. 2003). The most advanced kind were Crocodilians, the Eusuchians first appeared some 140 to 65 million years ago and the crocodilians of today all belong to this suborder. King and Burke 1989 reported that thee are of about 23 species found throughout the world today belonging to Family Crocodylidae which is further divided into 3 subfamilies a) Crocodylinae, b) the Alligatorinae and c) the Gavialinae. On the other hand, Crocodilians exist throughout the tropics and are considered “keystone species” that generally maintain ecosystem structure and function and recycling nutrients and maintenance of wet refuge in droughts as reported by (Thorbjarnarson 1992).Cott 1961; Pooley 1982 and Thorbjarnarson 1992 reported that these include selective predation on fish species.Crocodilian populations are threatened by overexploitation, hunting, skin trades, habitat loss and pollution (Thorbjarnarson, 1992). On the other hand, many species wide-reaching are exploited for their skins and many populations are threatened due to hunting for trade. Ross 1998 explained that the loss of any species of crocodilian would correspond to a significant loss of biodiversity, economic potential and economic stability.Nile crocodile and the history of EgyptThe Nile crocodile has traditionally played a very important role in the history of Egypt and the Nile River. The god Sobek, with the body of a man and head of a crocodile, was worshipped to venerate the strength of the crocodile while preventing “evil” interactions. In his honor, temples at Fayoum and Kom Ombo (Aswan) were erected during the Greek-Roman Period 200 B.CAncient Egyptians would keep crocodiles in pools and temples. They ornamented the crocodiles with jewels in honor of their beloved god, Sobek. The people of ancient Egypt worshiped Sobek in order to appease him, the crocodiles, and to insure the fertility of their people and crops.The Nile was very important to the people of Egypt, and so that Sobek was called the Lord of Faiyum, and was considered the god who controlled the waters. Water was necessary for the survival of crops, the success of trade, and the livelihood of fishing. These waters were filled with crocodile, so it was a matter of common sense to appease them through the worship of their leader, Sobek. Nile crocodile history: Nile valley and Lake Nasser Historically, the Nile crocodile was found throughout the Nile River and its tributaries, including the Rosetta Branch at El-Rahmaniya village (Flower 1933); however, its modern occurrence has been heavily impacted by the expansion of human populations and the creation of the Aswan Dam. While there are no formal reports, unreliable information suggests that in the 1950's professional hunters decimated crocodile populations for the unregulated skin trade, resulting in a very patchy distribution, even fears of extinction, throughout Egypt in the 1960's and 1970's (Ross 1998, Pooley 1980). While the construction of the Dam at Aswan negatively impacted the ability of the crocodiles to utilize the Nile River, the resulting formation of the Lake Nasser opened available habitat and crocodiles were colonizing the lake. It was a surprise for scientists to observe crocodiles spreading in the Lake and increasing in number, year after year. This may be because the Lake is now banked on both sides by the desert, and the human population has been thinned, and the environment became suitable and favourable for living and breeding of crocodiles. The question of where the crocodiles came from, whether it was from the upper Nile in Sudan or the lower Nile towards the In Chapter 2, the author gives detailed information upon the Lake Nasser habitat and ecosystem try to have a look on some of what he wrote. Chapter II General Characteristics of Lake Nasser LOCATION The Aswan Dam was built in 1902 and heightened twice in 1912 and 1934 to increase its storage capacity. Nevertheless/ the stored water was not adequate for agricultural development and great amounts of flood water were released annually into the Mediterranean Sea. In 1959, the construction of a rock-filled dam started on the River Nile, 17 km south of Aswan, 900 km from Cairo, which created one of the largest man-made lakes in Africa - the High Dam Lake (Fig. 1). The Lake extends from the dam itself in the north to the Cataract at Dal, Sudan in the south. The major portion of the Lake lies in Egypt and is known as Lake Nasser and Lake Nubia on the Sudanese side. Lake Nasser extends between latitudes 22° 00' - 23" 58' N and longitudes 31° 19'- 33° 19' E. The purpose of constructing the Aswan High Dam (AHD) was primarily to benefit the downstream side by controlling annual floods, provide irrigation to about two million feddans and generate electricity. Indirectly, however, the upstream side has also benefited because of the formation of the lake, which has created great possibilities for fisheries, navigation, agricultural production and even tourism. The region from Aswan to Adindan, which was previously an undeveloped desert, is already developed by controlled use of water from the reservoir (Bishi 2000). LAKE NASSER MORPHOMETRY The whole reservoir extends about 496 km, 292 km for Lake Nasser and 204 km for Lake Nubia. The area of the reservoir at 180 m level is about 6275 km2 of which Lake Nasser occupies about 5248 km2. The mean depth of Lake Nasser at 160 m level is 21.5 m as compared with about 25.2 m at 180 m level.The mean width of the Lake at 160 m level is 8.9 km, and 18.0 km when the water level reaches 180 m. Morphometric data of Lake Nasser at water levels of 160 and 180 m are presented in Tables 1 and 2.the deepest part of the Lake is the ancient river bed south the adjacent strips of cultivated land forming together the original river valley, called the central area of the Lake with its bottom elevation between 85 and 150 m above sea level. The side areas lie between 150 and 180 m a. s. l. The central part is considered as a flowing river-lake where the speed of the current is fast at the southern end of the Nubian gorge region (100-150 cm/sec). This speed is gradually reduced within a few kms to 10-20 cm/sec and in Lake Nasser to 0-3 cm/sec. The mean depth of this central part is gradually increasing from 10 m at the southern end to 70 m in the north. The bulk of the water masses coming from the south are passing through the central part, which forms about half of the total volume of the Lake (Entz and Latif 1974 and Entz 1976). The flood, which arrives at Aswan from Khartoum within one month before the High Dam was built, covers now the same distance in not less than 5 months but sometimes probably more than 12 months depending on Lake level and the strength of the flood. In chapter 3 the author study lake Nasser shoreline vegetation and he also identify the role of these vegetation types in relation to Nile crocodile life, have a look upon this chapter 3 Chapter IIIGRADIENT OF LAKE NASSER SHORELINE VEGETATION AND THEIR AND THEIR ROLE FOR NILE CROCODILE HABITATSABSTRACT. A delicate plant cover has developed during the last few decades along the shores of Lake Nasser, on the hand, the use of statistical methods ordination and classification techniques emphasize the groups of species and their distribution along the shoreline of Lake Nasser affected by the prevailing environmental conditions that in the same time affected on the lake Nasser ecosystem. Mainly the distribution of these species is robustly related to the moisture gradient as well as Lake Nasser water level. RESULTS AND DISCUSSION Vegetation analysis Identification of clusters (groups)According to TWINSPAN classification of the stands surveyed in the present study, four clusters of stands their vegetation, are objectively identified. Each cluster is named after the dominant species and identified according to its associated species as described below.Cluster I: Hyoscyamus muticus - Tamarix nilotica - and Glinus lotoides. The dominant species are Hyoscyamus muticus (P = 100%), Tamarix nilotica (P = 85 %), Citrullus colocynthis and Glinus lotoides (P = 57.1%). Other characteristic are Salsola imbricata, Pulicaria crispa (P = 42.5%).Cluster II: Tamarix nilotica - Glinus lotoides - Cynodon dactylon - Fimbristylis bis-umbellata. The dominant species are Tamarix nilotica (P= 100%), Glinus lotoides (P = 76.5%) and Cynodon dactylon, Fimbristylis bis-umbellata, Crypsis schoenoides and Heliotropium supinum. Cluster III: Tamarix nilotica - Phragmites australis and Rumex dentatus, and Heliotropium supinum. The dominant species are Tamarix nilotica (P= 100%). Cluster IV: Tamarix nilotica - Eragrostis aegyptiaca, Senecio aegyptius, Fimbristylis bisumbellata, and Cyperus laevigatus -. The dominant species are Tamarix nilotica (P= 100%). Based on the water supply and moisture content which controlling the vegetation distribution along the shoreline. CA analysis of the species in relation to the moisture content obviously indicates the arrangement of the species along the moisture gradient. AHC analysis separates the groups of species in relation to the moisture gradient which is recognizable in nature. A sequence in the arrangement of the groups of the species indicates the altitudinal zonation of the vegetation. Starting from lower to upper area or from lower slope to higher we can classily the vegetation structure into the following groups based on the soil moisture. The first group of species and that is characterized the stands that characterized by wet conditions (Amaranthus lividus, Crypsis schoenoides and Echiurn rauwolfii, Cynodon dactylon). The second group comprises the mesophytic species (Hyoscyamus muticus, Glinus lotoides, Amaranthus sp and Heliotropium supinum) associated with the mesic (these area that having or characterized by moderate or a well-balanced supply of moisture) conditions on the moisture gradient. The third group (Eragrostis aegyptiaca, Senecio aegyptius, Fimbristylis bisumbellata, and Cyperus laevigatus) is distributed along the moisture gradient from little mesic to mesic-dry conditions this come in harmony with (Springuel et al.1991). The fourth group (Tamarix nilotica, Phragmites australis and Rumex dentatus) occupies the dry end on the moisture gradient of Lake Nasser shoreline. These species typically grow on the upper part of the shores, subjected to epigrammatic inundations occurring less frequently than once a year on the other hand, these species looks like border along the shoreline and help Nile crocodiles for nesting and may they used as shelters and they moderate some time the nesting temperature or say they protect nests form the sun.Finally the desert perennials (Salsola imbricata and Pulicaria crispa) have a special position out of the recognized moisture gradient. They are native plants in the desert around the Lake and their growth seems to depend on the seed bank rather than on other factors. Along the shores of the lake both plants are present only in isolated locations and do not form a continuous zone.We conclude that the ordination and classification analyses used in the present study elucidate that the water regime of the Lake is the main factor controlling the growth of the plants and zonation of shoreline vegetation on the other hand the soil parameters have little effect of the spatial variation of vegetation and geographical gradient is less marked as reported by (Springuel et al.1991).According to the above data as well as the landsat ETM+ supervised classification that carried out in the previous chapter, Tamarix nilotica, Phragmites australis, Salsola imbricata and Pulicaria crispa are the most important plants for crocodiles nesting and they play a good role as shelters furthermore most crocodile nests located in/beside these vegetation, where moderate nests temperature. Vegetation types, role and dominant vegetation types Vegetation cover along the lake Nasser was analysis of the vegetation type which screened the nest site directly from the water only and which grows parallel to the stream. Vegetation cover around the nest was analyzed as the vegetation which occurred around the nest site .The vegetation cover surrounds the nest site and does not cover the actual nest chamber as that needs to be exposed to the sun for egg Incubation. The vegetation character along the lake Nasser shoreline or the lake banks, are fairly uniform and are not composed of a large diversity of plants. Based on our investigation and literature review species of vegetation around nesting sites play also an importance role where when the vegetation presence, that means the vegetation save the shade that it will cast over the nest causing it to cool down and try to moderate the air temperature . Vegetation also provides shade for the female crocodile that has to regulate her body temperature while guarding the nest against predators. Pooley (1969) reported that that soil temperatures in direct sunlight became unbearably high, thus shade becomes important for the survival of the female crocodile. Nevertheless, too much shade over the nesting site may alter the incubation temperature which will affect sex ratios in the nest, on the other hand at sites that the vegetation rare to occur and no shade, crocodile female, depend on, to wet her body then quickly go toward the nest and wet the sand, such that operation repeated more than time along the day, this come based on the author investigation and felid work in the lake. Also based up on our investigation the shape and the deep of the nests whole depend up on the soil substrata, which according to our survey where classified on sand, sandy rocky, sandy muddy or with alluvial deposits, and gravelly alluvial deposits, this point need more research in the future In chapter 4: the author discuses the Nile crocodile estimation in lake Nasser in details under this chapter and used the spot light methodology and double observer nocturnal spotlight count survey methods on the other hand we will try to give a shot summary about this chapter and we will discuss his result as follow in this part for further details please go to chapter 4 and chapter 4 part 2 in section of media coverage in this web site.Chapter IV: Nocturnal spotlight count survey methods for the estimation of abundance, distribution and population trend analysis of the Nile crocodile, Crocodylus niloticus, in Lake Nasser- Egypt See chapter 4 part2 to see location maps and tracking routes and crocodile sighting.1 Chapter 2: GENERAL CHARACTERISTICS OF LAKE NASSER………………………. 10 Chapter 3: GRADIENT OF LAKE NASSER SHORELINE VEGETATION AND THEIR AND THEIR ROLE FOR NILE CROCODILE HABITATS………………………………. 24 Chapter 4: Nocturnal spotlight count survey methods for the estimation of abundance, distribution and population trend analysis of the Nile crocodile, Crocodylus niloticus, in Lake Nasser- Egypt…………………………………………………………………………. 32 Chapter 4 part 2: Spotlight count, survey routes and sighted crocodile "Nocturnal spotlight count survey methods for the estimation of abundance, distribution and population trend analysis of the Nile crocodile, Crocodylus niloticus, in Lake Nasser- Egypt"…………… 59 Chapter 5: MORPHOMETRIC MEASUREMENT AND FELID ESTIMATION OF THE SIZE OF NILE CROCODILE IN LAKE NASSER- EGYPT………………………………. 74 Chapter 5 part 2: CAPTURE RECAPTURE AND RELEASE TECHNIQUE METHODS………………………………………………………………………………… 91 Chapter 6: Habitat vulnerability for the Nile crocodile (Crocodylus niloticus) - lake Nasser- Egypt…………………………………………………………………………………………. 97 Chapter 7: STUDY OF THE NILE CROCODILE NESTING HABITAT………………….. 125 Chapter 7 part 2: Lake Nasser important khors 3D simulation using Aster satellite images and Landsat ETM+ Habitat vulnerability for the Nile crocodile (Crocodylus niloticus) - lake Nasser Egypt……………………………………………………………………………….. 144 Chapter 8: DIFFERENT STAGES OF THE DEVELOPMENT OF FISH PRODUCTION OF LAKE NASSER "Comparative study in between past and present"……………………... 157 172
In chapter 5: The author discuses the: MORPHOMETRIC AND FELID ESTIMATION OF THE SIZE OF NILE CROCODILE IN LAKE NASSER- EGYPT And try to have a look up on some results and discussion in this chapter Morphometric data A total of 528 + 81*hatchling individual crocodiles were sighting 61 individuals crocodiles were captured between October 2009 and august 2010. Yearlings made up the majority of the individuals, reflecting their natural dominance in the population (Table 1) Male and female hatchlings were pooled due to the difficulties. In sexing hatchlings in the field using non-lethal techniques Table 1. Number of individuals captured per size class from 2009/2010 from Lake Nasser region, using nocturnal, and boat based techniques. Hatchlings could not be sexed reliably in the field using non-lethal methods. Regression analysisThe following were measured on every crocodile: head length (HL), snout-vent length (SVL), total length (TL), right hind foot length (HFL), neck girth (NG), tail girth (TG), chest girth (CG), and mass. HL was measured dorsally, while SVL and TL and vent were measured ventrally. Simple linear regression and logarithmic equations expressing the relationship between TL and VL,HFL,NG,TG,CG,HD vent and Body mass, and SVL and TL, HFL, HFL,NG,TG,CG,HD vent and Body mass by using the flowing equations (y = a + bx).Snout-vent length relationships: Total length According to our study, hatchlings were removed from the analysis due to their less increased in snout-vent length with increasing total length than the other size classes. On the study of the relationship in between total length and snot vent length relationship, the slope of other size show highly significantrelationship (r= 0.996 , P<0.001), which indicating a significantly higher increase in SVL relative to the increase in TL as animals grew longer. Generally male and female adults showed significantly different rates of increase and intercepts, with males showing a relatively higher increase of SVL: TL than females. The intercept for females was, however, non-significant.Snout-vent length relationships: Head length The lake Nasser population showed a significant relationship between head length and snout-vent length for all size, with HL increasing at a higher rate relative to SVL in smaller animals (Fig. 2). The slope of the HL: SVL regression decreased step-wise as crocodiles grew, with adults having the lowest head-length increase relative to SVL (r =0. 986, p < 0.001). Hatchling head length measurements showed more variation than other size and so the intercept for this regression was not significant
Snout-vent length: Head width There was a significant relationship in between the SVL: HW of Nile crocodile in Regression analysis of Lake Nasser, in according to fig. 1 (r=0.989, p< 0.001).On the other hand, the slope of regression in between SVL: NG, show high significant relationship, which means as the animals increase in snout vent length the Neck girth increased rapidly, however that may depend on some factor such nutrients, but in our case the nutrients in lake Nasser play a significant role and not contributed by any problem in animals growth.Snout-vent length relationships: Head depthThe slope of the regression of HD: SVL increases more rapidly as crocodile length (SVL) increases, showing that larger animals have significantly deeper heads relative to their length than smaller animals (r =0.987, p < 0.001 ). The regression trends for juvenile and subadults sizes show significant variation in the rate of increase of HD with increasing SVL. The rate of increase of HD with increasing SVL did not differ between sexes (p > 0.05). Snout-vent length: Head width There was a significant relationship in between the SVL: HW of Nile crocodile in Regression analysis of Lake Nasser, in according to fig. 1 (r=0.989, p< 0.001).On the other hand, the slope of regression in between SVL: NG, show high significant relationship, which means as the animals increase in snout vent length the Neck girth increased rapidly, however that may depend on some factor such nutrients, but in our case the nutrients in lake Nasser play a significant role and not contributed by any problem in animals growth.Snout-vent length relationships: Head depthThe slope of the regression of HD: SVL increases more rapidly as crocodile length (SVL) increases, showing that larger animals have significantly deeper heads relative to their length than smaller animals (r =0.987, p < 0.001 ). The regression trends for juvenile and subadults sizes show significant variation in the rate of increase of HD with increasing SVL. The rate of increase of HD with increasing SVL did not differ between sexes (p > 0.05). Snout-vent length: Tail girth, the slope of regression analysis of the relation in between the Tail Girth: Snout-vent length, show high significant relationship where (r=0.989, p< 0.001).Snout-vent length: Chest girth The slope of regression analysis of the relation in between the Chest girth: Snout-vent length, exhibited high significant relationship where (r=0.983, p< 0.001).Snout-vent length: Body mass The slope of regression analysis of the relation in between the Body mass: Snout-vent lengthexhibited high significant relationship where (r=0.921, p< 0.001), this relation as we discussed before that may dependant up on the nutrients and the amount of stomach food, so may the relation from animals to other and may also dependant on the time of feeding, so we think that this relation may also dependant also on the location, or said that the location and time play a significant role in that relation.Snout-vent length: VentThe slope of regression analysis of the relation in between the Vent: Snout-vent length exhibited slightly significant relationship where (r=0.885, p< 0.001) on the other hand Hind foot length: Snout-vent, show a moderate relationship (r=0.754, p< 0.001), see fig 2, table 2). Total length with the other parameters relationship The table below table 3 illustrating the regression relationship in between the Total length and the parameters (Neck girth, Chest girth, Body mass, Tail girth, head length, hind foot length, head depth and head width, vent, and the slope of the regression illustrated as in the following table 3.Total length: Head length Lake Nasser population showed a significant relationship between head length and Total length for all size, with HL increasing at a higher rate relative to HL in smaller animals (Fig.3). The slope of the HL: HL regression decreased step-wise as crocodiles grew, with adults having the lowest head-length increase relative to HL (r =0.994, p < 0.001). Hatchling head length measurements showed more variation than other size and so the intercept for this regression was not significant.Total length: Head widthThere was a significant relationship in between the TL: HW of Nile crocodile in Regression analysis of Lake Nasser, in according to fig. 3 (r=0.990, p< 0.001).On the other hand, the slope of regression in between TL: NG, (r = 0.989, p< 0.001) show high significant relationship, which means as the animals increase in total length , the Neck girth increased rapidly, however that may depend on some factor such nutrients, but in our case the nutrients in lake Nasser play a significant role and not contributed any problem in animals growth.Total length: Tail Girth The slope of regression analysis of the relation in between the Tail Girth: Total length, show high significant relationship where (r=0.991, p< 0.001) on the other hand, Total length: Chest girth, show a high regression analysis slope ((r=0.984, p< 0.001), as well as the relation in between the Total Length and Vent and hind foot length and (r= 0.873, p< 0.001, r=0.740, p< 0.001) respectively, as expressed the Hind foot print show moderately significant relationship and slightly high relationship in case of the vent relationship, and high relationship in case of the body mass (r= 0.923, p< 0.001), which means the no problem in the nutrients/food sources for crocodile in lake Nasser as well as may slightly difference in between location, but still no variation in between location as well as by time see table 3 and fig.3). DISCUSSION Morphometric According to our study it was noted that as crocodiles increase in length, the rate at which snout-vent length increases relative to total length, this may be an indication of their behavior, so that small crocodiles have relatively longer tails than large crocodiles. On the other hand, that can be illustrated due to the need to be vastly mobile to capture fast-moving invertebrate prey (so to be faster than the prey to capture), as well to being able or to have the ability for quickly and efficiently to avoid capture by predators. As they increase in size, the numbers of prospective predators decreases to eventually just humans and other crocodiles. Large crocodiles feed less often, on fewer, larger prey items and do not need to feed as regularly as smaller crocodiles that feed constantly throughout the year in Lake Nasser which come in harmony with (Wallace and Leslie 2007). According to our study and on using simple linear regression it was observed that the larger animals grow in girth at a much faster rate relative to an increase in length than do smaller animals, and that was clearly observed according to the close relationship and the close correlation in between the total length and tail girth, as well the close correlation in between the snout-vent length and the tail girth (see graphic), and so that added girth and mass is an adaptation that is required to control large mammalian prey. Lake Nasser water system characterized by a constant flowing current especially in the khors system but the small increase in tail length may possibly provide an animal with a unique swimming advantage, or run quickly from predators in Lake Nasser, or to avoid themselves from Lake Nasser fishermen in hydro-vegetation. The proportional rate of growth of HD to SVL decreased in hatchling and yearling animals was isometric in juveniles and subadult animals and then increased again in adult animals. The predominance of fish in the diet of juvenile and subadult animals (Hutton, 1987a) this may be illustrated that these animals do not need the additional strengthening of the jaw brought about by the allometric increase of the depth of the jaw. The associated increase in surface area for muscle-attachment with increased head depth would give larger animals a distinct benefit to handle larger mammalian prey, as well as providing the extra Strength/power to withstand powerful knocks to the skull by these preys. The swift ontogenetic shift in skull morphology does therefore not seem to be restricted to smaller animals (HW and HL), but also occurs at the onset of sexual maturity (HD) to prepare adults for larger prey. It was observed that the lack of adult captures reflects the ability of larger animals to avoid capture, mainly it was recognized that larger animals more sensitive than smaller animals in the wild habitat. The Nile crocodile growth rates are extremely changeable and thus, to predict the age of individuals on use the size-age curves a larger error will be resulted as reported by (Hutton, 1987c). However, given the variability in growth rates of juvenile animals, it is not possible to accurately estimate age using regression methods. Brandt (1989) found this in A. mississippiensis, Games (1990) in C. niloticus and Webb et al. (1978) and in C. porosus.Body condition indices Occasionally, as (Webb and Messel 1978a) noted that SVL was used as the basic index of body size because TL relied on the assumption that the tail was undamaged. However, this was not always the case. On the other hand, Webb and Messel (1978a) found that tail length was slightly sexually dimorphic. So we see that the accurate relationship to compare SVL with other parameters based on that the SVL as the basic index of body size. But mainly body mass varies with the amount of food in the stomach, and therefore not a reliable indicator of growth of animals in lake Nasser furthermore, the habitat type and whether conditions and seasonal variations and we also recognized that slopes also play a vital role and that come in harmony with the suggestion that given by (Webb et al. 1978). While SVL growth of Lake Nasser crocodiles was, for the most part, significantly correlated to the proportion of time spent in above average water temperature, the increase in condition for hatchling, yearling and juvenile animals was positively correlated to a rise in water level and negatively correlated to time spent in above-average water and air temperatures, we need to say that also water temperature play the vital role in Lake Nasser crocodiles life history, where the increase of feeding by the suitable temperature and the opposite is right. Interestingly an increased proportion of time spent in warmer than average water and air temperature decreased the RCF, while the proportion of time spent in above-average water level increased the RCF. This was probably due to the fact that in above average temperatures, energy was being put into active growth of the crocodiles, whereas in the high - water season, the over-abundance of food allowed the crocodiles to improve physical condition, Games (1990), found that juvenile crocodiles did not differ significantly in RCF values between sex, age, differing parasitic loads or the timing of the hot, wet season. However, RCF values differed between cool and warm periods. These findings showed that RCF values for juveniles were higher in the cool, dry period, due to higher water levels allowing crocodiles to exploit new food sources as well as in khors in lake Nasser than the open areas, where a high amount of food than, on the other hand, (Webb et al. 1991) suggested that the quantity and variety an the type of prey ingested has direct consequences for body condition. On the other hand, he also emphases that according to Crocodylus porosus juveniles showed similar growth rates, in different studies, when they had similar diets without changes.This illustrated that lake Nasser ecosystem enable crocodiles with high value of RFC and it varies from site to other and from khor to the others based on the food sources and types and quantity
CONCLUSION
A number of biotic and a biotic factor interact to determine growth rates, morphometrics and body condition indices of crocodilians. In the lake Nasser, the most significant influences were water level and temperature, diet and possibly the fast-flowing nature of the lake Nasser itself or said water fluctuation. While these influences were not unique to this crocodilian population, their combined effects may distinguish the physical characteristics of the individuals making up the lake Nasser population from other populations. The body design of crocodilians, while showing extreme conservation throughout their evolution, is phenotypically flexible which may allow for minor adjustments in response to environmental stimuli, as demonstrated by extant genera (Richardson et al. 2002).The close significant correlation and relationship in between parameters, exhibits the health of Nile crocodiles as well as the health of lake Nasser ecosystem during the time of the study although, lake Nasser ecosystem affected by several types of pollutants, which mean that Nile crocodile need further research to estimate its relationship with the lake Nasser pollutants and their effect on its life history and at what degree as well as the close relation in between parameters illustrated that no problems in the nutrients and food sources in lake Nasser.
In chapter 5 part 2 the author give a detailed information about the try to have alook on this chapter in section of media caverages
· Mapping habitats
· Habitat suitability patterns
· See the chapter 7 and you will find a detailed information upon nesting ecology.
In chapter 8 the author gives detailed information about the lake Nasser fishery from 1964/1966 to 2010
Chapter 8: DIFFERENT STAGES OF THE DEVELOPMENT OF FISH PRODUCTION OF LAKE NASSERComparative study in between past and presentSee the chapter in media coverage
In chapter 9 (the last chapter the author discussed the public awareness in / out lake Nasser in details ( see the chapter for further details ).
Workshop and Capacity Building for upcoming generations, fishermen, stakeholders and others Held in Aswan and Lake Nasser – Egypt On the behalf of community environmental education program of Nile crocodile
Workshop participants came from crocs team Prefectures. Different work units were represented, including community and district government leaders, prefecture. Most presentations and group discussions took place in space provided by crocs teams. Some good discussions were also had during meal times. Workshop trainers/facilitators, also community environmental education and different types of awareness for local communities and fishermen in Lake Nasser during the diurnal and nocturnal survey of Nile crocodile in Lake Nasser had been carried out and aimed to arise the public awareness of Lake Nasser fishermen, as well as, works extended to the Bedouins of Wadi Allaqi protected.Our project of Nile crocodile in the part of its community's environmental education more than 750 fishermen, 2000 student in different level of schools furthermore, faculty of science students were shared and take apart of our program of awareness, 3 important workshops carried out to raise the student awareness and to address the issue of Nile crocodile Lake Nasser. The main goals and objectives § To discuss current problems of Nile crocodile in lake Nasser and issues and try to find solutions as well other related problems such as the fisheries and fishery production in lake Nasser
§ To put the environmental issues among the concerns of the general public, and increase the area occupied by the social communication between the target groups and on top of these issues, the issue of the Nile crocodile in Egypt and to undergo interventions between the different audiences. § Impact on the surrounding communities to spread awareness of the environmental behavior and correct § Building human capacity in order to be able to cope with environmental problems including the problems of overfishing, pollution and global warming and its impact on the components of biological diversity. § To design strategy aimed to strengthen ties between the environmental work in conjunction with the various segments of the public (school students - parents - teachers - academics ...........etc) to protect the Nile crocodile and attempt to resolve conflict between him and the man inside and outside of Lake Nasser. § clarify the role played by the Nile crocodile in creating a kind of ecological balance between fishes of Lake Nasser, where the Nile crocodile is the top of the food chain in Lake Nasser ecosystem, which is attributed to him innocent in the deterioration of fish production in Lake Nasser, and provide factual evidence and figures facts that reflects the reality of Lake Nasser since 1966 to this day.
• General introduction• Introduction of all workshop participants• Session on Nile crocodile in Lake Nasser • Session on “Laws and regulations” in Egypt and environment law 4 for 1994 and the modified one No 9 for 2009 as well other laws• Group discussion on several main conservation problem areas
• Land cover and land use in Lake Nasser • Nile crocodile distribution in Lake Nasser • National nature reserves in Egypt
• Ecosystem services provided by Nile crocodile • Estimated number Nile crocodile in Lake Nasser based on based on our survey and compared with what published in the newspapers • Main environmental protection measures: • Laws and regulations• Nature reserve management• Working with local people and communities especially fishermen in and out of Lake Nasser • Nile crocodile surveys and monitoring should inform management decisions• Specifically, how to conduct Nile crocodile surveys: • Importance of environmental education and other community-based workKey issues discussed
Finally Human/ Nile crocodile interaction (conflict) tends to be the most serious problem according to the participants and take a lot of time in case of the felid work in Lake Nasser or in the community environmental education programme in held in Aswan/ Lake Nasser. Human/Nile crocodile conflict One of the most serious discussions were on the conflict in between the man in Lake Nasser, in general, and the Nile crocodile, it was difficult to convince the audience to the problem of Nile crocodile from the beginning, but it was necessary to publicize the hazards suffered by this animal and this object as an weak object, man destroyed nests eggs and killed young individuals, and dealer with all the possible trade operations of its member and leather trade. The rumours on the problem of the destruction of fisheries and publish it in the newspapers is nothing but it was sender words and it had no basis in scientific fact or confirmed it. Had to be this boot in the workshops that were presented in order to achieve the desired goal which is to raise the efficiency of present individuals and their involvement in the environmental problem we are facing, everyone at the end of lectures respond to us and with the issue of crocodile Nile and called for an increase of seminars, lectures, and environmental awareness programs for this organism. Target groups Targeted work to focus on primary school children and junior high schools participated from Aswan, where student from the Institute of Aswan girl's secondary school students and exemplary Institute Aswan lower secondary pilot for boys. Students participated as volunteers from the Faculty of Social Work in Aswan and the number of guests from the EEAA and the electricity distribution company in Aswan, on the other hand students from the faculty of science, south valley university.The targeted group in Lake Nasser was the fishermen, local Bedouins especially in Wadi Allaqi protected area, farmers along the shoreline of Lake Nasser.Notes about the community environmental education that carried out Environmental awareness within /out Lake Nasser program for fishermen in the lake (dialogue strategy has been carried out with the fishermen in Lake Nasser).We have designed a strategy to deal with hunters/fishermen of all classes and different ages in Lake Nasser, to estimate the dimensions of the real problem of the Nile crocodile in Lake Nasser from the mouths of fishermen honestly, we inform them that we are only researcher group and just want to recognize the problem and we did not ask one to make his name or anything indicated by or offered later on liability and then what we want just a chat dialogue, and only want the truth then comes by stages II, which depart from the same struggle between fishermen and the Nile crocodile and to identify dimensions of the problem between the two parties then came the third phase, a process of persuasion and illustrated with some examples and accuracy in the detection of numbers and comparisons and then review some of the production of Lake Nasser, and over the past years since 1966 since the first production of Lake Nasser, as well as the census number of cases and injuries suffered by the fishermen and to compare what is happening in Lakes in South Africa such as Tanzania and other man-what is happening in Lake Nasser from injuries or accidents, in fact not represent more that parts from thousand percent compared with other lakes in south Africa fro example.Targeted meetings with fishermen of about 750 individual fishermen of the lake we got to know through meetings with fishermen for example, the estimated numbers in each Khor been studied where the interviews in the day, and field work to the same location at night, in some cases their estimates were contrary to reality and sometimes comes close to the reality studied. As we got on the relationship between the fishermen and the Nile crocodile, amazing to see in many of the sites fishermen have become used to life with the crocodile in the lake but some defects object the Nile crocodile likes to kill and it does not benefit him or the lake.The majority of lake Nasser fishermen believed that the crocodile produces materials to purify the water in the lake, and we have rectified the information, the Nile crocodile has a great role in elimination the lake of dead fish, which is working to increase the bacteria and fungi in the lake water and then is already in the cleansing water of the lake.For this we try to ask them some questions depend upon their knowledge and time in Lake Nasser. The following some question of our question that we try to ask him whether in his camp or when he fishing.
Based on the above questions More than 60% of the fishermen confirmed to the day they see a crocodile or more one , either fishing or next to the fishing camp or to close to him, while the remaining percentage indicated that it is not necessary to see the crocodiles every day and they may change location from time to time. 85% of the fishermen considered that the presence of crocodiles in the lake runs on the lack of fish production, as it destroys the fishing nets for them and they have no interest in the lake and its predators and must be eliminated at the earliest opportunity, 10 % may considered that crocodiles have some benefits (fig.1). In accordance to the number of cases that have been attacked by crocodiles conflicting views are heading out the different sites and other known sites, persons and others not mentioned, or if one or more lists. At the same time as noted everyone can see crocodiles, but may not be able to know the actual number which is located in his district as he cannot precisely determine the length of them.Not only we done this simple questionnaire and the information that we have collected from the conflict between fishermen and the Nile crocodile in the lake, but we had to assess the behavior of these fishermen and explain to them the role played by the crocodile in the lake and its relationship to increase fish production in the lake, as he rarely attack anyone or never, on the other hand the attacks that was recorded from behind the fishermen who want to take the hatchling or destroy their nests or eggs, we mean that the crocodile attack, a defending for themselves or for their young.We conclude from this that we are working to raise environmental awareness for those men fishermen in the lake and explain the importance of the Nile crocodile and that it should not kill the crocodile or destroy the nests.
Workshops that had been carried out on the behalf of Nile crocodile comminutes environmental education program. The Nile crocodile project has organized three effective workshops targeted several groups, mostly students from schools, colleges, and nature conservation sector employers , teachers, educational sector of Aswan Aimed was to raise the environmental awareness among all target groups, this has resulted in workshops and achieved desired their objectives. § The first workshop carried out at 24 Jan. 2010 and held in Aswan. The workshop aimed to arise the efficiency of the nature conservation sector and Aswan branch of Egyptian environmental affairs employers to the importance of the Nile crocodile, Lake Nasser and the extent of the risks faced by this object as well as lengthy presentation to the formation of Lake Nasser from 1964/1966 and its stages for filling as well as the different stages of lake Nasser fisheries production since the formation of the High dam Lake. § The second workshop carried out at 10 March and held in Aswan, nature conservation sector, included a felid trip to Saluga and Gazal islands (the workshop report included). § The third workshop carried out in Aswan, nature conservation sector, included a felid trip to a felid trip to Saluga and Gazal islands 26 April 2010 (the report included).
finally try read the above chapters in details in section of media caverages in this web site
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Project number: 0925574
Awarded amount: $20,000
Awarded date: 04-09-2009
Continent: Africa
Country: Egypt
Ashraf Hussein Ibrahim Salem
“Conservation Ecology of the Nile crocodile” and Community Environmental Education
El Sadat Street, Egyptian Environmental Affairs Agency, Central Laboratory Building, Aswan Branch,
Aswan - Egypt
Aswan
81111
Egypt
Tel: Landline: (+20) 972312760
Mob: Mobile: (+20) 181019235
Fax: Fax (+20) 972312760