Coastal Zones: Uses, Development and Stresses

                                   

 

Gris Gris public beach

South coast

Aerial view of Cap Malheureux

North coast

The sandy beaches of Mauritius

Protection of Coastal Zones

Guidelines for Coastal Water Quality

Urbanisation of Coastal Zones

Rodrigues

Off Shore Islets

 

 

Introduction

Coastal zones are of great importance to Mauritius given that many economic and leisure activities take place there. It is home to many families of fishermen that depend on coastal fisheries for subsistence. The tourism industry has developed principally along stretches of sandy beaches and for the local population coastal zones are where much needed leisure activities take place.

Unfortunately, coastal zones are also recipients of land based pollution such as untreated domestic and industrial sewage, solid waste from dumps close to the shore and agricultural run-offs. The mining of sand, though banned since October 2001, has added to the pressures on the resources of the coastal zones.

Considerable pressure is exerted on coastal zone ecosystems and its resources. In spite of significant degradations, the country is failing to adequately address the pressing issues of the coastal zones. Economic pressures are still mounting and given the aim of Government to double tourism arrivals to 2,000,000 by 2015, it is unlikely that environmental or social considerations will be given much weight in the decision making process by authorities.

The competing and often conflicting demands for access to coastal zones by the population, property developers and the tourism industry together with the need to ensure that the marine and coastal ecologies continue functioning mean that an integrated approach to coastal zone management is urgently required but very difficult to put in place. The country still has no coastal zone management plan (although one is in preparation) and even if there was one, development pressures could make it barely functional.

What are coastal zones?

According to the Environment Protection Act 1991 the coastal zones meant:

" (a) (i) any area of seawater including any low-tide elevation, land, beach, islet, reefs, rocks, lying between the baseline and the highwater mark,
(ii) any land which is situated wholly or partly within 81.21 metres from the highwater mark,

(b) includes any estuary or mouth of a river and that part of a river, stream or canal which lies within 81.21 metres from the outermost point of its bank on the sea at high tide;"

The Environment Protection Act of 2002 which replaced the 1991 act, defined coastal zones as follows:

"coastal zone"

(a) means any area which is situated within 1 kilometre or such other distance as may be prescribed from the high water mark, extending either side into the sea or inland;

(b) includes -

(i) coral reefs, reef lagoons, beaches, wetlands, hinterlands and all islets within the territorial waters of Mauritius and Rodrigues;

(ii) any estuary or mouth of a river and that part of a river, stream or canal which lies within 1 kilometre from the outermost point of its bank on the sea at high tide;

(iii) the islands of Agalega and Saint Brandon, and other outer islets.

This legal definition being more inclusive and coherent than the previous one.

A geographical definition of coastal zones would include the following: the coastal plain, the continental shelf, the waters that cover this shelf and includes features such as bays, estuaries, lagoons, small islets and reefs. It is also the region where the marine and continental processes of erosion and deposition, interact giving rise to different types of landforms.

 

 

Ilot Bernaches

North East islet

La Preneuse public beach

West coast

View of lagoon

Rodrigues

 

 

 

 

 

 

The Continental Shelf

In spite of the limited extent of the Mauritian coast, barely 323 km in length, it comprises a great variety of different features. The presence of an appreciable and shallow continental shelf all round the island has determined in part the nature of the coastal features seen. For example the shallow shelf has enabled the development of coral reefs, which mainly thrive in shallow and warm waters. The reefs in turn shape coastal morphology.

 

Morphology of shores and beaches around the island

Formation of Land forms

Landforms that develop and persist along the coast result from a combination of processes acting upon the sediments and rocks present in the coastal zone. Waves, currents and tides are the most prominent processes affecting coastal morphology. Climate and gravity are also significant agents of change.

The Lagoon and Coral Reef Formation

Calodyne - North East Coast

 

 

 

Waves

Waves moving towards a coast are the most obvious of the coastal processes under consideration. As waves enter shallow waters they interact with the sea bottom. As a result sediment can become temporarily suspended and is available for movement by sea currents. The larger the wave, the deeper the water in which this process can occur and the larger the particles that can be moved.

Generally, small waves cause sediment, usually sand, to be transported toward the coast and deposited along a beach. Larger waves, during a storm for example, can remove sediment from the coast and carry it out to into deeper water.

Waves erode the bedrock along the coast largely by abrasion. Similarly, suspended sediment particles, pebbles and rock debris have an abrasive effect on a surface. Waves which have considerable force can break up bedrock simply by impact.

 

 

Tides

Tides are semi-diurnal and have mean amplitude of 0.8 metres and generally vary between 0.5 to 1.3 metres. The relatively low tidal amplitude means that tidal currents generated are of low magnitude. Hence their effects on coastal morphology are weak.

Climate, Winds and Gravity

The climatic elements of importance in the development of landforms are rainfall and wind. Rainfall is important because it provides the run off in the form of streams and is an important factor in producing and transporting sediments to the coast.

The importance of wind comes about in its relationship to waves. The presence of strong winds is associated with high energy waves. The direction and intensity of winds determines both the direction and energy of the waves.

Cyclones (Tropical storms) with their associated strong winds and considerable rainwater increase in magnitude the usual processes that affect landforms.

Gravity also plays an important role in coastal processes. It is indirectly involved in processes associated with wind and waves and it is directly involved through down slope movements of sediment and rock.

This role is particularly evident along shoreline cliffs where waves attack the base of cliffs and undercut the slope. It results, eventually, in the collapse of rocks into the sea or accumulation of debris at the base of cliffs.

 

 

Long shore currents

Waves usually approach a coast at an acute angle rather than head on and when waves enter shallow waters at an angle; they are bent (refracted). As this happens, the bent waves generate a current that runs along the shore and parallel to it. This current is called a longshore current. The current's speed depends on the power of the waves and their angle of approach with the shore. It can vary from 10 centimetres per second to over one metre per second under stormy conditions.

Waves and longshore currents together transport large quantities of sediment along the shallow zone adjacent to the shore.

Longshore currents may move in either direction along the shore depending upon wave direction. As this is determined in part by wind direction, it follows that the wind is the ultimate factor in determining the direction of longshore currents and the transport of sediment along the shoreline.

Typically waves lift up the sediment and longshore currents carry it along the coast.

In Mauritius, the coral reefs act as barriers and absorb most of the impact of waves. Those overflowing hit the shore almost orthogonally. However, where the coral reef barrier is absent, at river mouths for example, waves can approach the coast at an angle and produce a longshore current.

It appears (Reference 1 P 272) though that a longshore current exists along the western and south western coasts that causes a drift of sediment. It does not appear to be continuous and its strength has not been measured.

High frequency waves can cause the accumulation of considerable volumes of water in the lagoon, raising its level by up to 1.5 metres. This excess water then flows out of the lagoon through gaps in the coral barrier reef thus creating a current called an intra-lagoonal current which may reach up to 3.5 knots. This current can transport loose sediment on the lagoonal floor out to the gaps in the barrier reef.

 

 

Depositional and Erosional Coasts

There are two major types of coastal morphology. One type dominated by erosion and the other by deposition.

Erosional Coasts

Generally erosional coasts have little or no sediment in contrast to depositional coasts with abundant sediment accumulation.

Sea cliffs and wave cut platforms are characteristic of erosional coasts. Wave cut platforms arise when the face of the sea cliff recedes under wave action. In Mauritius erosional coasts occur mainly where coral reefs are absent. This occurs along part of the western coast at Pointe aux Caves and Montagne Jacquot and along the southern coast.

Cliffs – Southern Coast

Depositional Coasts

Waves and wave-generated currents significantly influence the development of depositional landforms. Waves crashing on the barrier reef lose most of their energy, but enough is left permitting sediment to be lifted off the reef flat, transported to the shore and deposited there.

In Mauritius, beaches are the most common depositional landform found along the coastline and sandy beaches made up of carbonate sediment are the most frequent forms seen.

 

 

 

 

 

Uses of coastal lands and lagoons

 

 

Coastal lands and The Pas Géomètriques

In Mauritius there is a particular legal regime that governs nearly all of the coastal land ownership. This law is known as the Pas Géomètriques Act of 1895. In this Act, the Pas Géomètriques are defined as being that strip of coastal land from the high water mark of the spring tides to at least 81.21 metres inland. This strip of land is by law State Land and is part of the “Domaine Public”.

The Pas Géomètriques Act covers nearly all of the coastline. Only in very few places like in Mahebourgh, Flacq and Rivière Noire are there fully private coastal lands from the high water mark onwards.

The State has the right to lease (but not sell) parts of the Pas Géomètriques for periods not exceeding 30 years but the leases can be renewed. This means that nearly all bungalows, hotels, public beaches and other amenities found on the beach front in Mauritius are on lands leased from Government.

The Pas Géomètriques were first set up by General Decaen in 1807 when Mauritius was a French colony. It was during the Napoleonic wars and the French rightfully feared a British invasion of Mauritius. The main purpose of the Pas Géomètriques was military because a coastal strip under Governmental control could be used for defensive purposes. It gave a clear view of the sea from the shore to spot any attempts to land troops and it allowed French regiments enough room to manoeuvre for counter attacks. Nevertheless, the British did land in 1810 at Pointes aux Canonniers in the North and took over the island from the French after a rather brief fight. It was the last time the island was military invaded.

The Pas Géomètriques is a wonderful tool that gives Government the possibility of managing the coastal zones literally at will. But what Government has done over the years is to privilege hotel and bungalow construction to cater for tourists above any considerations, social, aesthetic or environmental.

A historical overview of coastal land uses

Historically the first human settlements were in the coastal region of Mahebourgh where the Dutch built a small village and fort during the 17th Century. After they left, the French claimed the island in 1715 and settled on the coast initially at Port Louis and Mahebourgh, the only two places in mainland Mauritius where deep water ports were possible. After the abolition of slavery in 1835 by the British, liberated slaves left the sugar cane plantations and many but not all settled along the coast to take up artisanal fishing as a means of livelihood. Many human settlements now found on the coast probably originate from this period onwards. Artisanal fishery is still a very important activity for thousands of fairly impoverished families.

Sand mining at selected locations has been going for decades if not for the past 200 years. The sand extracted was used for construction purposes. With more than 800,000 tonnes of sand extracted yearly from the lagoon and inland deposits close to the shore, this activity was having a definitive impact on beach dynamics and was exacerbating beach erosion in numerous places along the coast. Fortunately, sand mining from the lagoon was banned in October 2001. There is anecdotal evidence that since sand mining was banned, beach erosion in some places has stopped and has even reversed.

Heritage

Due to the fact that many early human settlements were close to the coast, a number of interesting historical artefacts can be found there such as old sugar cane factories, lime kilns, military fortifications and old warehouses. A number of religious edifices are also found along the coastline.

Old warehouse at Bel Ombre – South Coast

The above is a delightful old warehouse found in Bel Ombre which was used at the beginning of the 20th century to store sugar before its despatch to Port Louis for export to the United Kingdom. Interestingly enough, because inland roads to Port Louis were difficult of use, the sugar bales were transported by boat to Port Louis!

Martello Tower (military fortification) at La Preneuse – West Coast

The above is a fine example of mid 19th century British military architecture in Mauritius. These towers were built on the west coast and close to Port Louis to repel any French invasions of the island which never came. The above tower has been transformed into a museum by Friends of the Environment.

Old Sugar Cane Factory at Belle Mare – East Coast

This is an extraordinary example of the ruin of a 19th century sugar cane factory. Many factories dotted the island then, some of which were found close to the coastal zones.

Old Lime Kiln at Flic en Flac public beach – west coast

Occasionally, old lime kilns can be found in very few locations around the coastline. The above can be found at Flic en Flac. It was used to transform corals into lime used for construction purposes. Very little has been published on the history of lime kilns. Judging by the state of masonry, this kiln probably dates from the late 19th century. Firewood was used to heat the crushed corals.

 

 

Coastal land use from the 1960’s till the present day

Before the 60's, there was little urbanisation of coastal areas. A few villages dotted the coastline with part of the coastal population earning a meagre living from the sea. Few people could afford bungalows and there were few tourists around. Indeed in 1968, the country welcomed barely 15,000 tourists. In consequence, the environmental stresses on coastal zones were minimal.

Grand Baie in the North West, a typical touristic village

The situation began to change in the seventies when Mauritius entered an unprecedented period of near continuous economic growth. Indeed, in 1970 the GDP was Rs 1017 million, it reached Rs 7389 million in 1980 and in 2008 it was Rs 231,843 million in current Rupees. In real terms it represents more than a 10 fold increase. This economic growth was fuelled by:

(1) A very large increase in sugar export earnings that went from Rs 341 millions in 1970 to Rs 1,549 million in 1975 due to a sudden increase in world sugar prices and reached Rs 11,198 million by 2006.

(2) A gradual but unrelenting growth in tourism arrivals that went from 27,650 in 1970 to 930,456 in 2008. Gross tourism receipts, estimated by the Bank of Mauritius reached Rs 41,213 million.

(3) A very successful drive towards industrialisation with export earnings of Rs 4 million in 1971 to Rs 33,610 million in 2006 in nominal terms.

(4) and a gradual growth in offshore financial services from 1989 onwards.

This economic growth has led to large and near permanent changes in land use patterns of coastal zones and of activities carried out there and in lagoons.

These changes are:

(1) Increases in haphazard urbanisation of coastal regions through the construction of bungalows and hotels on the Pas Géométriques and on off beach private lands, and the growth of coastal villages.

(2) growth in beach tourism,

(3) increases in the number of mauritians heading for the beaches for recreational purposes,

(4) increases in the number of leisure boats operating in the lagoon,

(5) greater fishing activity in and off lagoon. 

The Urbanisation of Coastal Zones - Bungalows

Economic growth over the last 3 decades has enabled many more people to buy property in the coastal regions and the number of bungalows shot up. Most of these bungalows were built on the Pas Géomètriques lands leased by Government.

The leases are for a maximum of 30 years renewable against a fee that was ridiculously low until now when Government radically changed the rent regime making it far more expensive to hold Pas Géomètriques land, to such an extent that current owners of bungalows have protested over the increases. Over the past decades, different governments have been generous in leasing away most of that land either to individuals or to hotel developers. The result of which is that in 1996 bungalow sites occupied 52 kilometres of coastal land representing 16% of the total. Though that does not appear to be such a high proportion, it is important to realise that the vast majority of bungalows are built on lands adjacent to sandy beaches.

Bungalows close to the seashore – North East Coast

The erection of bungalows tends to preclude the population from gaining access to those beaches, though this is unintentional in most cases. But on numerous occasions, owners of bungalows have erected fences and walls in order to prevent access to beaches by the public.

It is clear that any future governments will find it increasingly difficult to justify leasing off further tracts of Pas Geometriques to private individuals when the public is facing rather crowded public beaches with few if any amenities. In fact, public pressure will soon demand that leases not to be renewed and the land so freed to be transformed into public beaches with proper amenities. A perfectly reasonable demand.

Grand Baie Bungalows built virtually in the water! North West Coast

In many cases, bungalows have been built far too close to the sea frontage as can be seen in the above picture. There are many disadvantages in doing so. First of all it impedes the free passage of the public up and down the coastline. Secondly, with brick walls so close to the sea, waves will crash on those walls and thus create erosion. Thirdly, during cyclones or even bad weather, swells can flood these buildings.

Thankfully, after much convincing the Department of the Environment has agreed to develop a set back policy which states that no hard structures are to be built on the first 30 metres from the high water mark. Although it is only a policy, not a legal provision, no permits will be issued if this provision is not respected.

This provision which sounds fairly simple and straight forward will have a positive impact on the coastal environment by preventing sand erosion from happening in the first place. It will also consolidate the free passage of the public up and down the sea shore.

 

Coastal Land Uses in kilometres

Uses

1975

1990

1996

Public Beaches

18.06

18.9

26.6

Hotel Sites

9.87

29

41.9

Bungalows

51

52

52

Building sites

23.7

25

25

Miscellaneous Activities

8.5

15.2

12.78

Agricultural

102.6

23.7

17

Grazing lands

108.77

17.1

28.7

Under Vegetation

103.7

76.24

Coastal Road

16.1

16.1

Cliffs

10.2

10.2

Cliffs / Grazing

11.5

11.5

St Antoine Sugar Estate

 

4.5

TOTAL

322.5

322.5

322.5

Source: Ministry of Lands and Housing, Government of Mauritius.

From this table we can see the distribution of coastal land users. We note that the data given is old and has never been updated by Government, at least officially.

 

 

 

 

The Urbanisation of Coastal Zones

Tourism and the Hotel Industry

As from the mid seventies it was governmental policy to encourage tourism and so leased large tracts of Pas Géomètriques land at very low rents for hotel construction. This policy was highly successful for in 1972 there were only 25 hotels for the whole country with barely 1000 rooms whilst in 2008 the number of hotels reached 105 with more than 10,800 rooms. In the same period tourism arrivals shot from 48,797 to 930,456 whilst tourism earnings went from Rs 52 million to over Rs 40,000 million.

The vast majority of tourists come to the country to enjoy the beaches, the sea and the sun. Hence tourists are concentrated on coastal zones. Initially it was the northern and western coasts that were developed for tourism because of near year round sunny conditions. Gradually the eastern coast also witnessed major tourism hotel projects and as from 2000 the southern coast has seen a number of hotels being built there in spite of limited sandy beach frontage, windy conditions and oceanic swells.

A beach hotel - East Coast

It is beyond reasonable discussion that the tourism industry has played a pivotal role in the economic development of the country. It has boosted foreign reserves and provided employment. The influx of foreign tourists has increased the exposure of the public to the outside world and influences. It has spurred the development of service industries that cater for the need of tourists, like restaurants, travel agencies, car hire services, retail shops, bars & discotheques. For years, the public perceived the growth in tourism as basically a good thing. However the perception of the public is beginning to shift as the demands of the industry for even more land increases. 

The vast stretches of sandy beaches adjacent to unoccupied Pas Geometriques land, have enabled the first hotel developers to lease from Government, for a small sums of money, hectares of prime coastal land. In the seventies or even in the eighties, this aroused little attention from the public because few could afford to go regularly and frequently to the beach for a day out.

With economic growth, once the basic needs were more than satisfied, people naturally looked for better recreational facilities. Inevitably they turned to the sea and its beaches. Furthermore, the increased wealth enabled more people to purchase or erect bungalows from leased lands on the Pas Geometriques. Hence competition for access to sandy beaches inevitably arose among the three groups: hotel developers, bungalows owners and the public. The intensity of that competition increases because hotel owners do not like the general public enjoying the same stretch of beach as their clients, hence there is a tendency for the public to be denied beach access in front of hotels.

Indeed in 1990 some people from the tourism industry have unsuccessfully asked that beaches in front of hotels be privatised and closed off to the general public. Hence, an insidious form of segregationist policy takes shape whereby hotel clients and locals are discouraged from sharing the same stretch of beach. It is important to realise that on the sliver of beach in between the high water mark and the low water mark there is an inalienable right of way for any member of the public at any one point along the coast line. Indeed the Criminal Code (Supplementary) Section 110 states that “ any person, who, without authority, obstructs or prevents the free passage of a pedestrian on the seashore shall commit an offence and shall, on conviction, be liable to  fine not exceeding Rs 2000…In this section, seashore includes that portion of the seashore which is covered by the sea at high tide and uncovered by low tide

Interestingly enough the Pas Géométriques lands are not only State Lands as specified in the Pas Géométriques Act of 1895, but are also part of the “Domaine Public”, so is there not a case that any member of the public has, at very least a right of way along any beaches in the Republic, irrespective of whether the Pas Géométriques is leased or not? We are not aware that this question has been fully answered and its implications clearly spelled out. 

Unfortunately, the pressure to build new hotels directly on the beach frontage is relentless because tourism is a major contributor to the local economy and is highly lucrative. Very powerful commercial interests are at play in this sector. More hotels on the beach mean less beach frontage for the public.

As a rule Government has nearly always sided with hotel developers giving very little consideration to the legitimate needs of the population for public beaches. For instance, for years the public used to go to Le Morne to enjoy the beaches there. Unknown to the public most of the land there was NOT declared public beaches and promoters got leases for larger and larger tracts of land there. As from 1990, hotels were being built up there, reducing considerably public access in spite of heavy public opposition. By 1996 – 1997, very little sandy beaches were left at Le Morne for the public.

A view of Le Morne – A peninsula in the south west

 

 

According to 1996 figures, hotel sites occupied 41.9 kilometres of coastal zones which represent 13% of the total which does not seem to be considerable but again it must be remembered that hotels tend to be built along the most beautiful stretches of sandy beaches of the island. Furthermore, since 1996 the number of hotels has increased from 90 hotels to 105 in 2008.

We have calculated, from Government Statistics that for each 100,000 tourist arrivals there is need for 8 km of beaches for hotels, we have thus estimated that with more than 900,000 arrivals in 2008, 72 km of beaches must be occupied by hotels, representing 22% of the coastline, a very large increase from the 41.9 km occupied in 1996 which represented then 13% of the coastline.

The insistence from property developers to have prime beach frontage and the demand from the public for more public beaches with better amenities inevitably leads to uneasy situations that end up in confrontation.

 

The Urbanisation of Coastal Zones

The growth of coastal villages

Nearly every coastal village has grown in size through more or less uncontrolled urbanisation. Houses, bungalows, shops, commercial centres have sprouted as the economy grew. There has been little control over how this process unfolded and there were few guidelines. The result has been that a number of once sleepy villages have become fairly ugly. Grand Baie and Flic en Flac are typical cases with buildings that lack proportion and are not visually pleasing. Furthermore, massive constructions directly on the beach heads block views of the sea from coastal roads.

Fortunately, throughout the coastal zones, Government and District Councils have been able to at least enforce one major rule, no buildings on the pas Géométriques were allowed to be more than two storeys high. This simple rule has effectively prevented high rise buildings directly on the beach head which would have been visually inelegant if not plain ugly.

Recreational Purposes & Public Beaches

Over the years, coastal zones have become important centres of leisure activities for the local population in search of a welcomed break after a hectic week at work. The need for recreation increases steadily as Mauritius becomes a middle income country with a population with more disposable income and more stressed than ever before. A day out to the beaches is not only highly enjoyable but it is also affordable by nearly everyone, thus the reasonable demand for safe and pleasant access to beaches will continue to grow in the future.

According to the 1996 figures, public beaches total 26.6 kilometres which represent 8.2% of coastal land use. This figure increased to 39.18 km in 2003 according to the Beach Authority. A very welcomed increase, yet it could well be insufficient especially on the western coast of Mauritius closest to the main towns where most of the population resides.

Mon Choisy Public BeachNorth West Coast

Any government, present or future will have to come up with more public beaches to dissipate mounting public concern for a better access to beaches and better amenities on site. A visit to the hugely popular beaches at Flic En Flac (west coast) on Sundays is sufficient to convince anyone of the urgency of the situation, the public beach there is packed with people, cars and buses. Amenities like toilets and water points are far and few between, and thus totally insufficient. The same scenario repeats itself in the north at Mon Choisy and La Cuvette, two very popular public beaches.

Leisure Boating

Tourism has considerably increased the number of pleasure crafts operating in the lagoons round Mauritius, whether it be motor boats for water skiing or para-sailing, or the usual sailing crafts. The operation of pleasure crafts is now regulated by law.

Catamaran leisure boats at Flat Island – North of Mauritius

Artisanal Fisheries

 

 

 

Environmental impacts of human activities in coastal zones

 

 

Human activities with impacts on coastal ecology and environment can broadly be divided up into:

(a) activities that are situated in coastal zones,

(b) activities that are occurring elsewhere (principally inland).

The category (a) can be subdivided into the following activities:

Similarly category (b) can be subdivided into the following activities

 

 

Environmental Impacts of Hotel & Bungalow Construction and Operation on Coastal Zones

 

 

The actual construction of hotels directly on the beach head has significant environmental impacts. Very often, there are sediment run-offs into the lagoon and haphazard disposal of construction wastes into wetlands. When permission is given for works directly in the lagoon, such works very often involves dredging and excavation which increases turbidity when mud is disturbed and is carried away by currents to be deposited somewhere else in the lagoon, on corals for instance. Furthermore, often Government grants permission to remove beach rocks to create bathing areas as was carried out in the south of the island a few years back (2004-2005). Such works interfere with beach dynamics and interestingly enough, this has often resulted in beach erosion. A few years later the hotel promoters were forced to replace some of the rocks to mitigate the beach erosion they created in the first place!

Heavy construction works in lagoon 2005 – west coast

In the seventies and eighties it was very common for hotels and bungalows to build jetties that impeded greatly the long shore current which in turn caused local accumulation of sand in one place and sand erosion in another. These jetties also impede the free passage of the public up and down the seashore. At times there were even high walls that descended right into the sea so as to physically prevent people from walking in front of a number of bungalows. It took energetic action in the early nineties from authorities to gradually put an end to this disgraceful practice. Indeed, government workers were sent together with officials to pull down those walls and jetties thereby re-establishing long shore currents and also permitting the free passage of the public. Example: Grand Gaube

By 1992, hotels with more than 75 rooms must have, by law, a water treatment plant on site, it is not known whether all the different hotels' treatment plants are really adequate to cope with the load or whether some seepage does occur at times which could have adverse effects on the lagoon. Sometimes sewage treatment plants were built close to the seashore as was the case in 1990 in the north.

Sand erosion caused by the construction of piers and other hard structures close to the sea shore and by sand mining (thankfully banned in October 2001) is a significant problem as detailed in the Baird report of 2005. The seriousness of the problem can be gauged by the fact that the Government has, over the past years, built sea defences at certain places round the coast like Grand Baie, Cap Malheureux and Flic en Flac. The defences consist of placing at selected places gabions which are wire netting cages 1 metre cube in volume filled with rocks. The objective of this method is to hold sand in place and permit the local accumulation of sand. Unfortunately gabions tend to disintegrate with time for instance at Flic en Flac.

Heavy works in lagoon 2001 – Blue Bay Marine Park – South East Coast

 

 

Gabions at Cap Malheureux, north coast

View of a hotel in the north built very close to the sea shore

Another hotel in the north built very close to the shore

A number of hotels were built very close to the shore line with hard structures in the water like sea walls as can be seen in the above pictures. As mentioned above such hard structures promote sand erosion further up the coast and is a pesky problem to deal with until the source of the problem is addressed.

Hopefully with the adoption of the setback policy and its enforcement in future construction problems associated with sand erosion will be abated greatly.

 

 

 

Environmental Impacts of Hotel & Bungalow Construction and Operation on Coastal Zones (continued)

The clearing of sea weeds, corals and other rocks in the lagoon close to the shore has regularly been carried out to create suitable bathing areas or sky lanes for hotels. Though, in some cases, the clearing is fairly innocuous, on a couple of occasions, it cannot be said to be so. It needs reminding that sea grass beds are nurseries for fishes and other sea creatures.

In 1993, the Touessrok Hotel at Trou D'eau Douce (east coast) carried out very important works in the lagoon with the necessary Environmental Impact Assessment report. The government of that time informed the management that "the ministry has no objection to the implementation of the proposed works in relation to (i) the dredging of the inner cover and of the two channels (ii) dredged material treatment and handling onshore (iii) beach recharging and widening (iv) erection of a groyne and (v) the construction of an artificial breakwater to protect the cove beach, provided that the following conditions are observed" (Le Week End 20th of June 1993). Though the local fishermen went to court to obtain an injunction, it does not appear that they managed to influence the course of things.

At Balaclava ( west coast of Mauritius), where a marine park has just been set up, a couple of hotels obtained the permission to create water skiing lanes by clearing corals over a long stretch of the lagoon. Notably, The Victoria Hotel, in 1995, cleared corals for a water skiing lane 750 metres long and 30 metres wide and further proceeded, in 1996, to clear another site for the creation of a bathing site and this amidst much opposition from local fishermen who feared for their livelihoods. Needless to say that the hotel had the necessary permits and Environmental Impact Assessment reports to back up this operation.

From 1995 till 2000, promoters fought hard to have a hotel built on "ilot des deux cocos" in Blue Bay Marine Park. Their initial works in August 2000 did cause damage to coral fields in the vicinity. However for once Government had the initial works stopped and subsequently rejected their Environment Impact Assessment report in April 2001. It is worth mentioning that it is the first time that a hotel project had been rejected by the Authorities on purely environmental grounds. It is undoubtedly a landmark in environmental management in Mauritius. It is possible that from then on promoters might be a little more aware of the importance of sound environmental management for the tourism industry. Click here for further details.

Unfortunately, little is at present known on the impacts of hotel development on the coastal and lagoon ecology. Yet there is anecdotal evidence that points to sewage seepage from hotels into nearby lagoons in spite of most hotels having primary and secondary sewage treatment plants.

Bungalows built along the coastline have rarely been connected to the sewage system and disposal of sewage is done mainly through absorption pits or cess pits. It is possible that nutrient enrichment of the lagoon occurs through seepage of sewage to the lagoon. But that is at present purely speculative. Thankfully for the past decade considerable effort have been made to connect most of Grand Baie to the sewage system

In several places, bungalows and even hotels have been built on wetlands or marshy grounds, for example at Flic en Flac or Grand Baie. This has resulted in a drastic reduction of wetlands around the coast, hence wetlands are no longer there to act as natural filtering systems of either sewage or storm waters. The water table at Grand Baie has risen significantly, for example, and is now only a metre deep. Flooding and pollution by sewage is now a reality in parts of Grand Baie. At Flic en Flac also, construction of hotels and bungalows has been going on for years on marshy lands. And now certain parts of Flic En Flac are regularly flooded after heavy rains with little scope for a permanent solution to the despair of residents. It is important to realise that wetlands act as natural filter beds cleaning storm or rain waters before they enter the lagoonal system. Lack of wetlands inland can lead to sediments finding their way into the lagoon thereby polluting it.

 

 

Environmental Impact of the Recreational Use of Beaches

One of the main impacts of the use of beaches by the public on the environment is the fact that a fair proportion of the public fails to use the dust bins provided on the beaches for the proper disposal of solid waste. Hence, at times and on certain beaches, there is solid waste accumulating on site. This waste, apart from being unsightly and a source of bad smells attracting rodents, can drift into the lagoon waters thereby polluting it.

Furthermore, at certain places, the lagoon is used by some people as a huge and uncontrolled dumping ground. Regularly, non governmental organisations working in the field of the environment and professional divers team up to remove from the lagoon bottom large quantities of solid waste which found its way there. For example on the 7th of June 1997, during the "World Environment Day" divers removed from the lagoon of Blue Bay ( South of the island ) car and truck tyres, old nets, discarded plastic bags and bottles, broken plates and even radio sets!

At low tide, it is common for locals or tourists to go reef walking sometimes even at night. The potential for coral damage is evident. In the nineties undersea walking was introduced as a tourist attraction. This activity has lead to localised coral reef damage. At present authorities have ceased to issue new permits for this activity, though previous operators appear to continue their activities.

 

 

Environmental Impacts Pleasure Boats Operations

Anchor damage by pleasure crafts or fishing boats is thought to be a significant factor in the destruction of corals whilst oil seepage from motor boats can have an impact on lagoon health, especially in places like Grand Baie where there are lots of boats at mooring. Over the years there has been a fairly widespread effort to install mooring buoys especially at popular diving sites in order to limit anchor damage. There is evidence that this measure has helped to a certain extent. Boating operations in lagoons have often created conflicts with swimmers on public beaches when boat operators openly flout safety regulations and common sense by loading and offloading passengers for boat trips directly from public beaches and travelling at high speed close to the sea shore. Authorities had to demarcate bathing areas along popular beaches to limit accidents.  

Pleasure boats at anchor in Grand Baie – North West

 

 

 

Conclusion

Coastal zones are undoubtedly under heavy use, and pressure will not cease in the foreseeable future as long as there are significant increases in tourism arrivals and with more of the population going to the sea side for leisure activities. With the world economic and financial crisis of 2008 – 2009, tourism arrivals have begun to drop. Although no-one knows how far or how deep this present crisis will be, reductions in tourism arrivals will lessen pressures on coastal zones, thereby opening up a window of opportunity to put in place a coherent coastal zone management plan.

Indeed, it is high time that a comprehensive policy of coastal management be set up by government before irremediable damage is inflicted upon coastal zones. Already, there are signs that all is not well, a decrease in the catch of fishes over the years, nutrient enrichment of the lagoon due to sewage, sand erosion, industrial pollution are but a few of the problems that have to be addressed fully. As a fair share of the stresses on coastal zones originate inland, it is clear that coastal zone management cannot be seen in isolation from what happens elsewhere, making proper management a challenging and interesting task of great importance.



Bibliography

  1. Prem Saddul: Mauritius, A Geomorphological Analysis , Geography Of Mauritius Series, Mahatma Gandhi Institute 1995.
  2. Encyclopedia Britannica Vol 25 & Vol 16
  3. Government of Mauritius, State of the Environment Report 1991.
  4. Mauritius Marine Conservation Society, Bulletin D'Information, December 1997, Volume 18, No 3.
  5. IELS Press reviews of local newspapers 1990 – 2008

 

 

Date on the Web: 26th of January 1998

Last Update: 20th of April 2009