Tale of a Tiny Sand Artist

In this post under GREEN HERITAGE we try to explore the life of an amazing Sand Artist...

Walking on a sandy beach, if you see a galaxy of designs made out of tiny sandy balls, don’t you get excited? Watch closely, you will see small burrows and tiny creatures popping out, looking around with watchful eyes. He is our sand artist- the Sand Bubbler Crab! This little beach dweller is an expert sand sculptor. The intricate unintentional designs are born out of simple necessity- he has to eat to survive!! Motivation is simple, but mechanics are not!! A lot of attention is given to animals in the categories of huge size, strong body, fast feet, but in ‘art category’ certainly the Sand Bubbler Crab is the Unsung Hero. 

Galaxy of designs created by the tiny sand artist!! 

Sand Bubbler Crab, though tiny in size, has special characters. He is humble but mighty- he uses his claws to dig burrows, sifts through sand, feeds on micro-nutrients and can toss sand balls away! He is a sober hard worker- never gives up, when the high tides wash away all the artistic work, he continues patiently to create more! He is very meticulous- cleans and maintains his burrow that protects him from enemies. He is an excellent manager of time- works in breakneck speed without wasting any time to feed as much as possible between tides! He is very practical and clever- throws the sand balls away from the burrow, pushes them away from the entrance of his burrow! He is heroic- fights single handed against the intruders of his territory! He is a stylish walker too!! 

Watch him creating sand balls while feeding !! 

Don’t you think this Hero deserves a bio sketch? Here it goes….. 

The shoreline of west coast of Karnataka harbours mainly three distinct habitats: sandy beaches, rocky shores and estuaries. The sandy bay of the coast is inhabited by innumerable creatures and Sandy Bubbler Crabs are the most interesting ones. Sand bubbler crabs are the small crustaceans, around 1 cm across the carapace, and they are characterised by the presence of 'gas windows' on the merus of the legs.These crabs dig burrows in sand and live. During low tide the crabs come out of their burrows and feed on the organic matter in the sand.The first sign of an emerging crab is a near circular to hole - the opening of the burrow - from which the crab checks several times to see if it is safe to emerge. Once satisfied, it re-enters the burrow and begins clearing it of sand. The crab uses its claws to scoop up small amounts of sand, eats up organic matter on each sand grain particle, rolls little balls of left over sand and tosses them out. These are the remarkable-looking reminders which help them from searching for food in the same sand twice.These tiny balls of sand measure approximately 2-3 mm. The feeding activity continues till the high tide comes.The sand bubblers quickly run into their burrows to protect themselves from high tides. During high tide the balls get washed away and the sea wave action replenishes the sand with micro nutrients. When the high tide subsides, crabs again come out for their next feast!

The crab is getting ready to toss the sand ball!!  

The Sand Bubbler Crabs belonging to the genera Scopimera and Dotilla (Family: Dotillidae) are widely seen in west coast of Karnataka. So far eight species of Dotilla and fifty species of Scopimera are known. The mating behaviour of these tiny creatures is amazing. They mate both on surface and inside burrows. Wandering males mate sequentially with resident females whereas the resident males chase the females, capture them and take them to burrows. The surface copulation has higher success rate than the underground copulation.

Two crabs in confrontation to protect their territories 

 Sea birds prey on sand bubblers. Though there are no direct threats from humans to the population of sand bubblers, we speculate that the increasing number of motorised fishing boats which harbour on the sandy bay in West Coast of Karnataka and the resulting oil spillage might create extensive habitat loss for the sand bubbler crabs over a period of time. Our observations at the Dhareshwara seashore are worth mentioning. A decade ago there were a very few traditional fishing boats. But at present there are nearly 50 mechanised fishing boats at Dhareshwara. The sandy bay at this beach is getting continuously polluted due to fishing boat's oil spillage, which eventually trigger habitat loss. The disturbed ecological niche will subsequently hamper the food chain as well as harmonious living of these tiny creatures.

Practical and clever crab has avoided blocking of the entrance!! Look at the free path!! 

Next time if you walk along the sandy beach, look for intricate patterns of balls. You can’t imagine in your dreams that a littered beach can be so beautiful!! Quickly take out your camera and capture the video of the action packed sequences of Sand Bubbler Crabs. Watch the video on your stressful day. It is really a stress buster!!

CAUTION!!- Crab’s eyes are watching you!! A tiny shade on sand will alert the crab and within a blink of an eye it runs and hides inside the burrows!!

Dhareshwara- The 'Rock'ing Shore

In this post under GREEN HERITAGE we explore some facts about Dhareshwara Rocky Shores in Western Ghats.

The rocky shores are one of the most fascinating of all ecosystems, packed with a wide array of marine life and uniqueness in structure and complexity. They are important spots with ecological, physical, aesthetic, and protective significance along the long stretch of the shoreline. Their very existence is important and essential for the functioning of the web of life along the shoreline.

Rocky Shores during low tide 

Sea beaches and shores are formed by sufficient loose rocky or sandy material and a suitable coastal climate which allows the sediments to accumulate. Rocky shores are steeper than sandy shores. This difference is the result of the different permeability of sediments and the frequency and intensity of sea waves. Rocky shores have higher permeability and much of the upcoming waves percolate into the bottom. A combination of waves and tides shapes the rocky shore and ultimately influences the survival of specific species of marine fauna. Wave action is another physical factor which results in the formation of Exposed Shores (more wave action) and Sheltered Shores (less wave action). 

West Coast of India is a unique place where the blue waters of Arabian Sea and the lush green rain forests of Western Ghats collage. Rocky shores are found wherever the western ghat hill ranges have stretched till Arabian Sea. Among the ecologically sensitive niches, the rocky shores are extremely intricate in marine biodiversity. The rocky shores of Uttara Kannada district of Karnataka State on the West Coast of India harbor rich marine fauna and flora diversity which is a unique natural heritage evolved since time immemorial. There are 15 rocky shores in Uttara Kannada district, among them Dhareshwara rocky shores have the highest biodiversity and harbor the richest marine fauna spanning from sponges to fishes. Some rocky shores of the district are under the control of the Indian Naval Base, the Sea Bird.

Dhareshwara rocky shores are not only the home for abundant varieties of marine creatures but are also an important nursery area for varied marine flora. This habitat also provides lots of food for fish. They add aesthetic value to the long stretch of sandy bay, protect the shoreline by controlling sea erosion activity, and are the source of some marine molluscs and crabs (which the locals depend on for food) etc. Dhareshwara rocky shores harbor all zones, i.e., low tide, intertidal and high tide zones, and it is amazing to see how the distinct marine creatures adapt and survive in each zone, as well as tolerating high temperature, desiccation and adverse climatic conditions.

Amazing creatures- Mother nature protects them 

colourful marine life 

Mother Nature protects all creatures. Plants and animals here are able to live both in air and water; they are able to survive the loss of almost 70 % of their body water during dry periods, and, in addition, are able to cope with freshwater rain when exposed and high saline seawater when submerged!! Many animals avoid sun, drying air and predators such as birds, by staying in cracks and crevices or under rocks or in their own burrows at low tide. Some sessile animals such as barnacles and oysters close their valves tightly to avoid drying when the tide goes out. Some molluscans either associate with other species of marine creatures or group together to avoid desiccation during summer. They come out to feed when covered by water. Many marine creatures confined to rocky shores are well camouflaged and appear to be invisible!!

Harmonious life: Co-existing marine creatures

Dhareshwara rocky shores are filled with an amazing diversity of marine life. Some species are beautiful, others bizarre, and some are tricky — but they all are important and deserve our attention as well as protection. Any altering of the hills attached to the rocks or vice versa will create imbalance and destruction of sensitive habitat of rocks resulting in species loss as well as coastal erosion. The rocky shores are most essential habitat for the survival of marine fauna which are confined to it, as these creatures can live only in this habitat and not on sandy shore. Hence, preserving the rocky shores and its integrity is most essential for conserving the rare marine biodiversity treasure of Dhareshwara for future generations.

Marine flora supports numerous marine fauna

The shore bird,one of the predators of rocky fauna

It is worth mentioning the recent case of conserving the hill and rocky shore habitat by local people. In spite of being within the ambit of "No Development Zone" of the Coastal Regulation Zone Act, there were attempts to cut the hills for farming and other activities. It was the villagers who came forward to stop these illegal activities. It is noteworthy, the youths of fishermen community of Dhareshwara, who are born and brought up there and fully aware of the importance of the natural wealth they inherit since time immemorial, volunteered in mobilizing the four communities of the village and upholding the scientific facts about the importance of rocky shore. The combined efforts of biologists and the youths compelled the Karnataka Biodiversity Board to constitute an expert committee which gave the verdict to conserve the integrity of hill and rocky shore. This instance proves beyond doubt that community involvement can help in the conservation activities. Educating the locals about their natural heritage will further strengthen future conservations.

Youths & leaders of Dhareshwara who stopped hill cutting & saved the Rocky Shores

Dhareshwara rocky shores are saved for the time being. It may not be a happy end in case of other rocky shores. What needs to be seen is, how many sincere environmentalists and biologists are ready to support the locals, educate them and if situation demands stand by them till the happy end.