Озеро Палич: история, экология и природа Сербии.

Lake in North Bačka District, Serbia

Lake Palić (; Palicsi tó) is a lake from Subotica, near the town of Palić, in Serbia. It covers an area of The average depth of the lake is With the surrounding area it forms the protected Nature Park Palić, which covers .

Despite popular belief, Lake Palić is not a remnant of the vast Pannonian Sea which covered this area and completely drained out some 600,000 years ago. It is estimated that both the Palić and Ludoš lakes originated in the early Holocene, around 10,000 years ago, when the last major changes in the surrounding terrain occurred. Prior to that, since the draining of the sea, the European climate was much colder, with the exchange of the cold and dry and the warm and wet periods. Alternatively, being frozen and defrosted, the rocks crushed under the ice and crumbled into the dust, which formed sand and loess. The winds would then disperse the loess into the valleys of the Danube and Tisza rivers to the southeast. On the wet grounds, the loess became more compact, becoming thinner and claylike. The surrounding dried land became more and more elevated thus creating the depressions which began to collect water. The process was helped with the erosion which was caused by the water flowing into the depressions. Due to the unstable hydrological regime, the lake constantly disappeared and reappeared through history. The idea that the lake was remnant of the sea was influenced by its geographical location (in the bed of the former sea) and the fact that the water in the lake was salty. It is more likely that both lakes and the nearby river of Körös ér are remnants of the former rivers which spilled over the Pannonian basin. Surveys showed that the loess layers are younger than the alluvial ones, so the lakes can't be remains of the former Danube's flow as the wind would naturally cover them with sand and loess.

The lake was mentioned for the first time in June 1462 when Hungarian king Matthias Corvinus bestowed it to his mother, Queen Mother of Hungary, Erzsébet Szilágyi, as part of the puszta like Csongrád County. It was mentioned as Palij. In Ottoman inscription from 1580, it was recorded as the village of Palegyhaza in Subotica nahiyah. The writing says the village has 10 houses. and that all pay taxes.

Over 200 bird species live in the protected section of the lake. During the emptying and refilling of the lake in the 1970s, artificial island made of the dried sludge were formed. They became known as the birds' islands and are today the only nesting location of black headed gull in Serbia. Surrounding shrubs are habitats of some of the most endangered birds in Serbia, like the migrating pygmy cormorant and razorbill. The ecological situation in the lake began to sharply deteriorate in the early 2010s. The 2018 tests showed that the major pollutant of the water are fecal bacteria. It is estimated that it will take at least 5 years for the lake to heal. Measurements in July 2022 showed that the water fits the microbiological criteria, but not the physical chemical and hydrobiological levels as there were still lots of nitrogen, phosphorus and blue green algae in the water. The water remained unusable for both drinking and swimming.

In the spring of 2019, it was decided to fish out the Prussian carp, omnivorous and voracious fish, which became abundant in the lake. In several months, over 20 tons of Prussian carp were fished. After the project was done, results showed the first improvement in the quality of the lake water since 1998. Though still categorized as the lowest, fifth category and not suitable for swimming, the water had less ammoniacal and nitrite compounds, and less algae while zooplankton Daphnia, which feeds on phytoplankton, reappeared in the lake. Another problem is the poaching. Apart from the direct damage in reducing number of animals (including the protected European pond turtle), it also affects the natural purification of water. The main catch for the poachers is the zander, which, as a predator, is very important in the lake's food chain. Situation with Prussian carp turned out to be worse than expected: it was estimated that there are 120 tons of this fish in the lake in total, but 190 tons were actually fished out. Further expropriation needed for the buffer zone was conducted in 2019–2020. The entire surrounding area was already expropriated in 1974, when the lake was emptied. However, the erosion since then eroded the banks, so the privately owned parcels which were further from the lake, are now on its banks. The buffer zone consists of four layers: 1) reed bed, in the water itself, which prevents the erosion of the banks by the waves and forms habitat for the birds; 2) bank slopes, inhabited by the herbaceous plants and habitat for the reptiles; 3) grassy areas, used only by those who administer and watch the protected areas; 4) pedestrian and bicycle path, with benches and stops where possible. In order to create the buffer zone, a monoculture of wild blackberry shrubs which spread all over the lake, had to be eradicated. It was replaced with other plants, mainly alfalfa, which prevent expansion of the invasive herbaceous plants. In February 2020, it was reported that some bird species, previously absent, were spotted at the lake. Fishing out of Prussian carp showed that small populations of indigenous species survived in the lake, some specimen weighing up to This prompted the second phase of the biomanipulation of the lake. In December 2021, after 10 years of discontinuation, fish stocking with autochthonous species resumed. Predatory wels catfish was reintroduced first, in order to control the population of invasive Prussian carp. Combined with temporary fish bans, in order to allow for the fish to spawn to greater numbers, and monitoring of the number of fish, future stocking batches will include northern pike, zander, common carp, and later other species. Common reed has also been transplanted in the stocked sections, to provide shelter and spawning areas. The "Ekolakus" project, however, continued till the end of 2022, when the report for the 2019–2022 period was published. A pumping station, of sewage system, and of delivery lines which push wastewater into the water treatment facility were built. Water was upgraded two classes up, from the V to the III category, which makes it acceptable for recreation. Water in sector I, where purified water is poured into the lake, overtook the water from the touristic sector IV in quality. Waste from 1,500 houses and 1,000 individual septic tanks was directly poured into the Palić Ludаš canal in 2019. Since then, 682 houses were connected to the Subotica's sewage system, while the wastewater from the canal is conducted into the water treatment facility. Amount of phosphorus in the water was cut in half: from in 2019, to in December 2022. 6,800 seedlings were planted in the buffer zone along the bicycle pedestrian path along the lake. Instead of expected 50 tons of Prussian carp, a total of 273 tons were fished out of the lake. Still, the report concluded that, despite the progress, it is not realistic to expect that Lake Palić will soon become a clearwater lake, without risk for the swimmers. In April 2023 it was made public that the farm of the Subotica District Prison was illegally dumping animal waste in the lake. It was overpopulated with pigs and sheep, so the warden Dušan Suvajac ordered digging of the canal, deep and long, to conduct the overflow of waste into the lake, instead into the septic tanks. According to the whistleblower and prison guard Đorđe Glušac, the prison's management overpopulated farm animals for their own schemes, and in order to avoid the suspicion of frequent emptying of the septic tanks, they dug a canal. It took a while since he reported this to the ministry of ecology until it was made public as the institutions were just moving the case back and forth. Local authorities refused to comment, but on the very day the case was sent to Subotica the canal was hastily filled and hidden under the bales of hay. Suvajac was sent to retirement in March 2023. In November 2022, an illegal dump right next to the bank was observed. By May 2023 it almost doubled, even though it is on the lot of another public company, Subotica's City communal company.

On 31 May 1950, a small zoo with only three animals (bear, monkey and parrot) was opened above the northwest corner of the lake. By 2020, Palić Zoo grew to , with being available to the visitors, and hundred species with 450 individual specimens. It is known for the wast animal spaces, surrounded by an arboretum with 320 plant species and a nursery garden. Core of the park are several oak trees, planted in the 1710s. The zoo has over 150,000 visitors yearly. Lake Palić has a relatively short summer season. Influenced by the Hungarian border wellness and spa centers which operate the entire year (Mórahalom, Szeged, Makó, Gyula), the idea of building a wellness complex with the spa was launched in 2006. Master plan for Palić was made in 2007 and the revitalization plan in 2014. The works stalled so in February 2020 the government stepped inn and changed the contractor giving it deadline of 8 months to finish the works. Despite claims of the local tourist organization that number of tourists grew, the corresponding minister Rasim Ljajić said that the government had to intervene since out of the 18 priority tourist destinations declared by the government, Palić is the only one where number of visitors decreased. The lake is partially encircled with the long pedestrian and bicycle path. but due to the COVID 19 pandemic everything was postponed for March 2021. As the works on all projects dragged on, local political tensions arose. Local authorities addressed the state government to intervene with the contractors, at the same time announcing construction of the new, luxurious hotel in the same area as the other projects. In June 2022 it was announced that the aqua park will be finished by December 2022, costing almost €14 million in total. This was then prolonged to 31 May, 31 July, and end of August 2023, before the park was finally opened on 15 September 2023.