Jamal Abdun Nashr, Semarang – Mangrove expert from the Faculty of Maritime Affairs and Fisheries at Diponegoro University, Rudhi Pribadi, criticized the construction project of the Semarang – Demak toll road. He argued that the national strategic project connecting Demak to the borders of Semarang would cut off the contact between mangroves and seawater.
According to Rudhi, [the life of] mangrove depends on tides of seawater. "If a toll road is made in the form of a dam, the contact with sea water is cut off and it will not be ideal for mangrove growth," he said on Monday, July 11, 2022.
He explained that the construction of the toll road would relocate 45 hectares of mangrove trees that are already a dozen years old. Indonesia is a country with the largest mangrove forest, yet also logs a very high decline in the mangrove forest.
The shrinking area of mangrove forests in Central Java was due to land conversion. "Indirectly, reclamation changes the sea level," he said.
To date, mangrove trees play a vital role in maintaining balance in coastal areas. The loss of mangrove areas would affect the biota that lives in it. "Another function of mangroves is to provide oxygen and absorb carbon," Rudhi underlined.
Similar criticism from ITB
Almost a year ago, in a webinar discussing the sinking of Jakarta, which was also attended by Central Java Governor Ganjar Pranowo, an oceanographer from ITB Hamzah Latief voiced similar complaints regarding mangroves on the coasts of Semarang and Demak.
Hamzah observed that Semarang experienced rapid changes in the coastline from 1990, 2000, 2010, and 2019. The shoreline could far back rapidly up to one kilometer. At that time, he hoped that the planned toll road project, as well as the embankment project for the toll road segment of Kendal-Semarang, would not harm the mangrove forest.
"Semarang Bay is a spawning ground. If it is gone, don't expect fish in the Java Sea anymore," said Hamzah.
The progress of sea embankment toll road construction
The Indonesia Toll Road Authority (BPJT) of the Public Works and Housing Ministry targeted the construction of the Semarang-Demak toll road section 2 to be completed by the end of 2022.
On the project's negative impact on the environment, the ministry claimed it was working with the regional government to prepare a mangrove land relocation program around the construction of the toll road section 1 covering a total area of 46 hectares.